HPT Mag. Vol.39 No 2/2021 - The next step in the green revolution: Heat Pumps with Thermal Storage by HPT Magazine

Heat Pump System improved HT-BTES Efficiency p. 21 Heat Pump integrated Thermal Energy Storage for Demand Response VOL.39 NO 2/2021 ISSN 2002-018X ”HEAT PUMPS AND EFFICIENT COOLING TECHNOLOGIES HAVE AN IMPORTANT ROLE IN REACHING THE GOAL OF NET ZERO" RELEASE OF IEA’S REPORT NET ZERO BY 2050 The next step in the green revolution: Heat Pumps with Thermal Storage H eat P umping TechnologiesMAGAZINE A HEAT PUMP CENTRE PRODUCT HPTI E A p. 7 The Highlights of the 13th IEA Heat Pump Conference p. 27

Disclaimer IEA HPC Neither the IEA Heat Pump Centre, nor any person acting on its behalf: makes any warranty or representation, • express or implied, with respect to the accuracy of the information, opinion or statement contained herein; • assumes any responsibility or liability with respect to the use of, or damages resulting from, the use of this information

All information produced by IEA Heat Pump Centre falls under the jurisdiction of Swedish law.

H eat P umpingMAGAZINETechnologies

Published by Heat Pump Centre c/o RISE - Research Institutes of Sweden, Box 857, SE-501 15 Borås, Sweden Phone: +46 10 516 53 42

Editor in chief: Monica Axell Technical editors: Jessica Benson, Sara Jensen. Markus Lindahl, Sofia Stensson - RISE - Research Institutes of CarolineSweden. Haglund Stignor, Johan Berg, Caroline Stenvall - IEA Heat Pump Centre Language editing: Teknotrans AB Front page reference: Image from Rotterdam ISSN 2002-018X

©Copyright:HeatPump Centre (HPC) All rights reserved. No part of this publi cation may be reproduced, stored in a re trieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the Heat Pump Centre, Borås, Sweden.

Editor in chief: Monica Axell Technical editors: Caroline Haglund Stignor, Ola Gustafsson, Sara Skärhem, Anneli Rosenkvist, Kerstin Rubenson - Heat Pump Centre.

Heat pumps have an important role to play in the future energy system. The IEA's Roadmap for the Global Energy Se ctor, Net Zero by 2050 that was published in May states that the heat pump market should grow with a factor 10 until 2050 to reach a net zero energy system in 2050. This very important topic is addressed in both the foreword and one of the news articles in this issue. April and May was important months for the heat pump market. Not only the IEA report was published but also the 13th IEA HPC conference took place in Jeju. Due to Covid 19 the conference was held as a successful hybrid event with presentations from all around the world. You can read a summary of the contents of the conference in the news se

Ongoing

Thection.topical

HeatPublisher:Pump Centre P.O. Box 857, S-501 15 BORÅS SWEDEN Tel: +46-10-516 53 www.heatpumpingtechnologies.orghpc@heatpumpcentre.org42

In this issue

Topical

Disclaimer HPC: Neither the Heat Pump Centre, nor any person acting on its behalf: makes any warranty or representation, • express or implied, with respect to the accuracy of the information, opinion or statement contained herein; • assumes any responsibility or liability with respect to the use of, or damages resulting from, the use of this information

All information produced by Heat Pump Centre falls under the jurisdiction of Swedish law.

IEAPublisher:HeatPump Centre PO Box 857, S-501 15 BORÅS SWEDEN Tel: +46-10-516 55 hpc@heatpumpcentre.org12 www.heatpumpcentre.org

The central communication activity of Technology Collaboration Programme on Heat Pumping Technologies (HPT TCP) Foreword: Heat Pumps and Storage, by Paul Column:FriedelFrench building regulations: A key driver for heat pump market deployment by Michèle Mondot and Valérie Laplagne HPT News Annexes in HPT TCP Articles Heat pump system improved HT-BTES efficiency, by Olof Andersson Heat Pumps and Thermal Storage: Canadian Perspec tives, by Justin Tamasauskas

SimulationsGluesenkampof

The State of Art of Heat-Pump integrated Thermal Energy Storage for Demand Response, by Kyle R. Grid-Responsive HVAC Cooling Measures via Ice/PCM storage, by Bo Shen

NationalEvents Team Contacts24154352127313536 VOL.39 NO.2/2021 ISSN 2002-018X https://doi.org/10.23697/5rz3-x622

articles of this issue are all addressing the in tegration of thermal energy storages in heat pumping and cooling systems. Two different types of thermal energy storages are covered, and they are both most likely impor tant for the energy system of the future. Storage in the form of bore hole systems and thermal storages integrated as a part of the heating/cooling system of a building. The former solution provides seasonal storage of energy, and the latter solution provides short term energy flexibility to the electri city grid. Enjoy your reading! Sara Skärhem, Editor Heat Pump Centre

Front page: SENS, Sustainable Energy Solutions, www.sens.se

©Copyright:IEAHeat Pump Centre All rights reserved. No part of this publi cation may be reproduced, stored in a re trieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the IEA Heat Pump Centre, Borås, Sweden. Published by IEA Heat Pump Centre c/o RISE - Research Institutes of Sweden, Box 857, SE-501 15 Borås, Sweden Phone: +46 10 516 55 12

FOREWORD VOL.39 NO 2/2021 HPT MAGAZINE 3

The only way to achieve this is to broaden our focus. We cannot afford to be content with a highly efficient heat pump alone. Instead, we need an integrated solution for heating and cooling, where heat pumps and storage units are seamlessly integrated into the energy system.

For starters, the IEA itself has announced its roadmap to a net zero carbon society by 2050. This report is nothing short of a revolu tion. For the first time, the IEA is proposing a radical and sudden break in the way we manage our global energy sector. We should stop looking for new fossil energy sources right now, and we should drastically accelerate the transition to a carbon-neutral in dustry, emission-free transportation, and renewable heating and cooling. Secondly, a Dutch court has ordered Royal Dutch Shell to cut emissions by 45% of 2019 levels by 2030. This unprecedented court order is the first time a commercial business is being held responsible for possible future environmental impact. Could this really be the start of a new take on the energy transition? Are we starting to understand that a sudden and dramatic transition to renewable energy is to be preferred over an uncertain future with uncontrollable global warming? I do indeed hope so!

» Maximal compactness

» Maximal affordability Depending on local conditions, the best implementation strategy can be selected. The next step then is to establish a package of specific policy support measures, tailored to that strategy. The technical solutions are available already; our present task is to establish and develop new heat pump and storage markets.

The thematic articles in this magazine all focus on the integration of heat pumps and storages, to help us begin to understand the challenges ahead. Because indeed, the times they are a’changin.

Heat Pumps and Storage

Paul Friedel Annex 55 Operating Agent Business Development Holland, Harderwijk/Rotterdam, Thefriedel@bdho.nlNetherlands

We have identified four of those strategies:

As I am writing this foreword, social media are inundated with euphoric and optimistic posts about the global energy transition.

» Maximal efficiency (traditional focus of research and policy)

Within Annex 55, Comfort and Climate Box, participants from 11 countries are participating to delineate and accelerate the market for integrated heat pump and storage systems (or Comfort and Climate Boxes). One of the main recommendations is to start working with implementation strategies for heat pumps and thermal storages.

To make the transition happen, all sectors must act. In particular, the heat pump market will have to grow at breath-taking speed. Not only in existing markets, but also in new markets, such as cold climates, densely packed cities, retrofit buildings and industrial processes.

» Maximal flexibility

4 HPT MAGAZINE VOL.39 NO 2/2021 COLUMN

In January 2022, RT2012 will be replaced by a new regulation, RE2020, which will reinforce building energy consumption requirements and implement new environmental requirements, such as reducing CO2 emissions from the building, mainly during its use phase. First to be implemented in residential buildings, the regulation will support the deployment of thermodynamic systems and restrict the use of other systems, such as boilers or Joule effect heating systems.

French Building Regulations: A Key Driver for Heat Pump Market Deployment

Today, the implementation of European Ecodesign and Energy Labeling regulations for heat pumps, air condi tioners and chillers introduces a new characterization of their performance through seasonal energy efficiency.

In an application of the European Directive on the Energy Performance of Buildings (EPBD 2010/31/EU), France implemented the RT2012 regulation for new buildings with a calculation of their energy consumption expres sed in kWh/m² per year. In addition, by legislating the use of renewable energy with a minimum of 5 kWh/m² per year or the use of a heat pump water heater with a minimum COP of 2 in individual residential buildings, the French regulation has accelerated the success of this latter technology, which has taken precedence over many other renewable energy technologies. The regulation has thus strongly contributed to the penetration of heat pumps in new building construction: heat pumps for heating (mainly air-to-water units) rose from around 50,000 units in 2012 to 175,000 in 2020. For heat pump water heaters, 115,000 units were installed in 2020 compared to 30,000 in 2012. Since its application, the RT2012 regulation has been amended to take into account technological advances in heat pumping products. This adaptability has enabled innovative heat pump technologies to emerge, such as heat pumps providing two or more services (heating, domestic hot water, cooling, ventilation), hybrid units, heat pumps using waste water or solar collector as a heat source, CO2 transcritical heat pumps. Specific featu res, such as free cooling or geo cooling, can also be taken into account.

When applied, this regulation is expected to significantly contribute to meeting the challenges of global war ming in the building sector through the deployment of heat pump technologies, while requiring minimum energy efficiency thresholds for each heat pump technology.

The R&D efforts carried out by the Annexes of IEA HPT TCP represent an important contribution to the technological development of heat pumps and the demonstration of their relevant use in various applications. National or regional regulations are also an efficient driver for accelerating the market penetration of heat pumps. The French regulation RT2012 is one successful example of such a regu lation that has ramped up the roll-out of heat pumps.

Discussions are underway within the CEN-CENELEC Coordination Group “Harmonization/ Coordination ErP / EPBD” Task Force to establish calculation methods on the energy performance of buildings based on the se asonal performance data declared according to the Ecodesign regulations. France will contribute to this Task Force by leading a project that brings together CETIAT, CSTB, EDF and UNICLIMA that aims to evaluate different calculation methods to be proposed for standards or future revisions of the French regulation.

In line with product standards, building regulations in France will continue to play a key role in the deployment of heat pumps in new buildings as well as existing buildings.

VALÉRIE LAPLAGNE Uniclima (French Association for Heating, Cooling and Ventilation Industry) Head of renewable heating sectors, heat pumps, solar thermal and biomass MICHÈLE MONDOT Cetiat (Technical Centre for HVAC Industry) Direction of Development and Partnerships Thermodynamic Systems Project Manager

The market penetration of heat pumps is also linked to the confidence that prescribers and customers have in the energy performance of products. This confidence relies on the certification of product performance, and the French regulations have always encouraged it, so far based on COP values.

building energy codes

Please

In addition, other defined key milestones, are “no new sa les of fossil fuel boilers by 2025” and that “50% of hea ting demand is met by heat pumps in 2045”, see Figure 4.1 below (page 152 in the report). The share of existing buildings retrofitted to the zero-carbon-ready level need to increase from <1% in 2020 to 20% in 2030 and >85% in 2050. The corresponding share for new buildings must be 100% already in 2030. The stock of installed heat pumps needs to increase from 180 million units in 2020 to 600 mil lion units in 2030 (more than triple) and thereafter a ten fold increase to 1800 million units in 2050, see Figure 3.29 below (page 145 in the report). IEA's Net Zero by 2050 – A Roadmap for the Global Energy Sector equipment stock by type and useful space heating and cool reference all figures as: 'International Energy Agency (2021), Net Zero type Over 85% zero-carbon-ready by 2050, reducing (2021), Net Zero by 2050, IEA,

Release of

b Chapter number 3 Figure number 29 Figure title Global building and heating equipment stock by

and useful space heating and cooling demand intensity Key point

VOL.39 NO 2/2021 HPT MAGAZINE 5 HEAT PUMPING TECHNOLOGIES NEWS

average final heating PrimaryLabels y axis Billion m² left title Building envelope right title Heating equipment stock Right y axis Billion units DATAFIGURE LEFT graph 2020 2030 2050 Retrofit ZCRB 0,517 39,20 167,00 New ZCRB 1,850 37,10 197,00 100755025400300200100 2020 2030 2050 100)=(2020Indexm²Billion Retrofit ZCRB New ZCRB Other Heating Cooling Building envelope Intensity (right axis): 4321 2020 2030 2050 unitsBillion Coal and oil Gas District heat Biomass Solar thermal Hydrogen Heat pumps Other Heating equipment stock Figure 3.29 Global building and heating equipment stock by type and useful space heating and cooling demand intensity changes in the NZE Over 85% of buildings meet zero-carbon-ready building energy codes by 2050, reducing average final heating intensity by 80%, with heat pumps meeting over half of heating needs. Figure reference: International Energy Agency

The special report released by IEA on May 18, 2021 shows that the pathway to the critical and formidable goal of net zero emissions is narrow, but it brings huge benefits. The report shows that heat pumps and efficient cooling technologies have an important role in reaching the goal. The pathway requires an unprecedented transformation of how energy is produced, transported and used global ly. Climate pledges by governments to date – even if fully achieved – would fall well short of what is required to bring global energy-related carbon dioxide (CO2) emissions to net zero by 2050 and give the world an even chance of limiting the global temperature rise to 1.5 °C, according to the new report, Net Zero by 2050 – A Roadmap for the Global Ener gy TheSector.report is the world’s first comprehensive study of how to transition to a net zero energy system by 2050 while ensuring stable and affordable energy supplies, providing universal energy access, and enabling robust economic growth. It sets out a cost-effective and economically pro ductive pathway, resulting in a clean, dynamic and resilient energy economy dominated by renewables like solar and wind instead of fossil fuels. The report also examines key uncertainties, such as the roles of bioenergy, carbon captu re and behavioral changes in reaching net zero.

Global building and heating

of buildings meet

Building on the IEA’s unrivalled energy modelling tools and expertise, the Roadmap sets out more than 400 milestones to guide the global journey to net zero by 2050. These in clude, from today, no investment in new fossil fuel supply projects, and no further final investment decisions for new unabated coal plants. By 2035, there are no sales of new internal combustion engine passenger cars, and by 2040, the global electricity sector has already reached netzero emissions.

6 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS

Most of the global reductions in CO2 emissions between now and 2030 in the net zero pathway come from technologies readily available today. But in 2050, almost half the reductions come from technologies that are cur rently only at the demonstration or prototype phase. This demands that governments quickly increase and reprioritise their spending on resear ch and development – as well as on demonstrating and deploying clean energy technologies – putting them at the core of energy and climate policy. Emissions from light industries, such as e.g. paper, food, vehicles etc need to decline by around 30% by 2030 and around 95% by 2050 in the NZE (Net Zero Emission Scenario). In contrast to the heavy industries, most of the technologies required for deep emis sion reductions in these sub-sectors are available on the market and ready to deploy already today. This is in part because more than 90% of total heat demand is low/medium temperature, which can be more readily and effi ciently electrified. For low- (<100 °C) and some medium- (100-400 °C) tem perature heat, electrification includes an important role for heat pumps (accounting for about 30% of total heat demand in 2050). In the NZE, around 500 MW of heat pumps need to be installed every month over the next 30 years, see Figure 3.20.

The special report is designed to in form the high-level negotiations that will take place at the 26th Conference of the Parties (COP26) of the United Nations Climate Change Framework Convention in Glasgow in Novem ber. It was requested as input to the negotiations by the UK government’s COP26 Presidency. The full report is available for free on the IEA’s website along with an online interactive that highlights some of the key milestones in the pathway that must be achieved in the next three decades to reach net-zero emissions by Read2050.the press release from IEA and the full report here > Figure 4.1 Selected global milestones for policies, infrastructure and technology deployment in the NZE. There are multiple milestones on the way to global net-zero emissions by 2050. If any sector lags, it may prove impossible to make up the difference elsewhere. Figure reference: International Energy Agency (2021), Net Zero by 2050, IEA, Paris. All rights https://www.iea.org/reports/net-zero-by-2050reserved. graph heat OtherIndustryTransportBuildings

FIGURE DATA LEFT

Electricity and

2010 2011 2012 2013 2014 2015 2016 2017 Power 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Buildings 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Transport 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Industry 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 40353025201510-5052020 2025 2030 2035 2040 2045 2050 CO₂Gt Buildings Transport Industry Electricity and heat Other 2045 150 Mt low carbon hydrogen 850 GW electrolysers 435 Mt low carbon hydrogen 3 000 GW electrolysers 4 Gt CO2 captured Phase out of unabated coal in advanced economies 2030 Universal energy access 60% of global car sales are electric 1 020 GW annual solar and wind additions All new buildings are zero carbon ready Most new clean technologies in heavy industryatdemonstratedscale All industrial electric motor sales are best in class No new ICE car sales 2035 Overall net zero emissions electricity in advanced economies Most appliances and cooling systems sold are best in class 50% of heavy truck sales are electric 7.6 Gt CO2 captured No new unabated coal plants approved for development 20212025No new sales of fossil fuel boilers 2040 More than 90% of heavylowproductionindustrialisemissions 2050 Almost 70% of electricity generation globally from solar PV and wind More than 85% of buildings are zero carbon ready 50% of heating demand met by heat pumps Phase out of all unabated coal and oil power plants Net zero Aroundelectricityemissionsglobally50%offuelsusedinaviationarelowemissions90%ofexistingcapacityinheavyindustriesreachendofinvestmentcycle50%ofexistingbuildingsretrofittedtozerocarbonreadylevelsNo new oil and gas fields approved for development; no new coal mines or extensionsmine Figure 3.20 Share of heating technology by temperature level in light industries in the NZE. The share of electricty in satisfying heat demand for light industries rises from less than 20% today to around 40% in 2030 and about 65% in 2050. Figure reference: International Energy Agency (2021), Net Zero by 2050, IEA, Paris All rights https://www.iea.org/reports/net-zero-by-2050reserved. Share of heating technology by temperature level in light industries in the NZE Please reference all figures as: 'International Energy Agency (2021), Net Zero Chapter number 3 Figure number 20 Figure title Share of heating technology by temperature level in light industries in the NZE Key point The share of electricty in satisfying heat demand for light industries rises from less than 20% LeftLabelschart axis Left axis label Right chart axis Right axis label left title Heat demand by technology right title Heat demand by sub-sector DATAFIGURE 2050 2030 2020 2050 2030 Mining and construction 5025 4101 3400 Food and tobacco 5810 5183 4660 Machinery 3566 3115 2818 Textile and leather 1441 1473 1510 Transport equipment 1590 1321 1092 Wood and wood products 689 664 629 Fossil fuel heater 16 200 Biomass heater 103 86 Electric heater 398 285 Hydrogen heater 162,00 10,60 Heat pump 0,14 0,13 Other heat sources 42,80 59,60 25% 50% 75% 100% 202020302050202020302050202020302050 Fossil fuel heater Biomass heater Electric TransportTextileMachineryFoodMiningOtherHeatHydrogenheaterheaterpumpheatsourcesandconstructionandtobaccoandleatherequipment Low/medium temperature heat demand by technology Heat demand by sub sector High temperature heat demand by technology Sub Technologysectors

Opening remark from NOC Chair Min Soo Kim

VOL.39 NO 2/2021 HPT MAGAZINE 7 HEAT PUMPING TECHNOLOGIES NEWS

Congratulatory address by Hee-ryong Won, Governor of Jeju Province Heat Pumps – Mission for the Green World April 26 – 29, 2021, Ramada Plaza Jeju Hotel, Jeju, South Korea By Professor Minsung Kim

On Monday, 26 May, the first day of the Conference, six workshops were held fully online actively involving around 200 participants. In the workshops, on-going and recently finished HPT Annex projects were introduced. The up-todate technologies discussed were heat pumping technolo gies related to smart grid connection, energy storage, and nZEB integration. In addition, low GWP refrigerant issues, cooling CCB (Comfort and Climate Box) solutions, and large demo-projects held the focus of the participants.

The Highlights of the 13th IEA Heat Pump Conference

Six influential plenary speakers presented their vision of the heat pump industry. The introduction of global heat pump markets and policies made by the first three speakers was followed by three eminent speakers providing excellent summaries on key heat pump system technologies. Mechtild Worsdorfer, IEA Director for Sustainability, Technology and Outlooks provided the opening plenary speech “Heat Pumping Technologies in Clean Energy Transitions”. She spoke of the

Conference Program Workshops

Welcome speech from Stephan Renz (IEA HPT TCP Chair)

Summary of HPC2020

The 13th IEA Heat Pump Conference (HPC2020) was held on April 26-29, 2021. Due to the COVID-19 outbreak, the con ference was held on both online and offline platforms. The offline venue was the Ramada Plaza Hotel Jeju, Korea. This year’s HPC 2020 was unique in not only the hybrid platform but also the program which featured all phases of heat pumping technologies. Despite the enormous challenges of the pandemic, the conference was successful, and atten dance exceeded our expectations. I could not be prouder of the commitment and efforts that went into making this conference possible. Despite the discomfort of remote discussions and online presentations, six plenary speeches from renowned spea kers and 201 technical papers enlightened the conference. More than 370 participants from 26 countries attended the conference, listened to meaningful presentations, and had fruitful discussions with experts from around the world on scientific and technological heat pumping issues.

Opening Ceremony

The opening ceremony of the 13th IEA Heat Pump Confe rence was officially held at 9 am KST on April 27, 2021 with a welcoming address made by Stephan Renz, Chair of IEA HPT TCP. Opening remarks were provided by Min Soo Kim, NOC (National Organizing Committee) Chair and Hee-ryong Won, Governor of Jeju Province, who delivered a congratu latory message.

Plenary Speakers

Martin Forsén, President of EHPA (Euro pean Heat Pump Association) presented the efforts of the European Commission to reach climate neutrality by 2050 in his pre sentation “The European Legal Framework is Well Set for a Massive Roll-out of Heat Pumps - but More Efforts are Needed”. In his speech, he emphasized how the energy system integration strategy with electrification based on heat pumps will double the share of heating produced by heat pumps by 2030, reaching 50-70% by 2050.

Thursday, April 29 On the last day of the conference, many interesting papers were presented. Topics ranged from state-of-the-art de humidification technology, food-storage systems and heat pumps for nZEB.

Didier Coulomb, IIR Director, presented the low GWP chal lenge and barriers. Among the keynote speeches, the wa ter vapor high temperature heat pump was introduced by Di Wu from Sanghai Jiao Tong University.

The National Organizing Committee (NOC) of the 13th IEA Heat Pump Conference would like to thank each and every person who contributed to this year’s conference. Also, we would like to call for continued dedication in pushing this field of science forward. We wish you the best and until the next time we meet, please be safe and healthy. See you all in two years in Chicago, Illinois.

Saikee Oh, Vice President of LG Electro nics, provided excellent summaries on recent air-source heat pump technologies. He also presented some fundamental bottlenecks as well as the cutting-edge heat pump technology that will overcome them.

8 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS potential heat pumps have in reducing the carbon foot print. For the Paris Agreement, a 3-pillar action plan consisting of greater deployment rates across all applications, the integration of heat pumps with power systems, and enhan cing heat pump technologies were emphasized.

After three days of technical sessions, the closing cere mony was held. After the opening remarks by Per Jonas son, IOC Chair, the Peter Ritter von Rittinger International Heat Pump Awards (RvR Awards) were presented. The RvR Award is the highest international award in the air conditio ning, heat pump and refrigeration field. As individual awar dees, Jussi Hirvonen, Director of the Finnish Heat Pump Association and Prof. Ruzhu Wang, Shanghai Jiao Tong Uni versity received RvR Awards. The Center for Environmental Energy Engineering (CEEE) at the University of Maryland received an RvR Award as a team. To promote student activities in this hybrid conference, a Global Student Video Competition was held. This competi tion provided an opportunity to create a video to exchange ideas and relevant knowledge on the topics of heat pump applications, environmental issues, energy, or what stu dents do in the laboratory. The video from RWTH Aachen University won the gold medal for their video entitled “Sherlock HiLmes: The Adventure of the Hardware in the Loop Investigations of Heat Pumps - A Case of Efficiency”.

Closing Ceremony

Min Soo Kim, President of SAREK (Society of Air-conditioning and Refrigerating Engi neers of Korea) and NOC Chair, presented “Korean policy for green world and heat pumping technologies”. He introduced the New Deal strategy of the Korean Govern ment which will invest KRW 73.4 trillion for transitioning to a low-carbon, green economy.

Noboru Kagawa, Professor of the Natio nal Defense Academy in Japan, presented experiences caused by health problems and how the pandemic has changed the design of HVAC systems in the presenta tion “Clean and Safe Air by HVAC Systems – Laws and Advanced Technologies in Japan”. The presen tation showed that accumulated knowledge can improve HVAC technologies. An overview of related laws and new technologies in Japan was given. Technical sessions

Tuesday, April 27 After the plenary speeches, the twelve general technical sessions were opened. An invited speaker, Dr. J.B.V. Red dy from the Government of India, presented the facts and policies on air-conditioning and cooling in India.

Xudong Wang, Vice President of AHRI (Air-Conditioning, Heating, and Refrige ration Institute) presented the transition to flammable low GWP refrigerants. The presentation covered the current status of developing relevant codes and standards in the US. It was clear after the speech that more research and efforts are needed to enable safe transition to low GWP refrigerants in the future.

Following the award ceremony, the promotion video of the 14th Heat Pump Conference was broadcasted. The confe rence will be held in Chicago, Illinois in the US on May 15–18, 2023. The proposed theme is “Heat Pumps – Resilient and Efficient”.

Closing Remark

Wednesday, April 28 In the morning session of the second day of the conferen ce, Tetsusiro Iwatsubo presented on innovative thermal management R&D projects by NEDO. In a session on low GWP refrigerants, various papers on policy and technical considerations were reported. Bamdad Bahar, President of Xergy Inc., gave an overview of hydrogen compressors for heat pump systems. Mr. Bahar also gave several more interesting presentations introducing heat pump techno logies of the future. Tor-Martin Tveit introduced the very high temperature heat pump applied at a pharmaceutical research facility.

Prof. Wang’s major contributions re lated to heat pumping technologies include adsorption heat pumps, desiccant based heat pumps and dehumidi fication, vapor compression heat pumps, absorption heat pumps, and heat pump applications in green building en ergy systems and industrial waste heat recovery. He has written 12 books regarding Refrigeration and Heat Pump Technologies (3 in English published by Wiley, Elsevier and Springer respectively). His publications have been exten sively cited, thus he has been recognized as 2017 & 2018 Clarivate Highly Cited Researcher in the world.

» Dr. Yunho Hwang, Co-Director and Research Pro fessor » Dr. Vikrant Aute, Co-Director and Research Scien tist » Dr. Jiazhen Ling, Assistant Research Professor

» Dr. Reinhard Radermacher, Director of the Center and Minta Martin Professor of Engineering, Profes sor of Mechanical Engineering

» Mr. Jan Muehlbauer, Faculty Specialist and Labo ratory Pressrelease Rittinger Award 2021 >

The Winners of the 2021 Rittinger Award

In a ceremony held digitally at the closing session of the 13th IEA Heat Pump Conference in Jeju Korea on April 29 2021, the winners of the prestigious Peter Ritter von Rittinger International Heat Pump Award, the highest interna tional award in the air conditioning, heat pump and refrigeration field, were presented.

The team from the Center for Environmental Energy Engi neering that received the 2021 Rittinger Award consists of:

VOL.39 NO 2/2021 HPT MAGAZINE 9 HEAT PUMPING TECHNOLOGIES NEWS

M.Sc. Jussi Hirvonen, was the initiator of heat pump business in the Finnish market and because of his tireless work, Finland has become one of the leading countries using heat pumps for space heating. Jussi’s 20 years of remarkable lifework in the heat pump sector also includes a large number of commitments in different positions and organizations which have forwarded heat pump business locally and glo bally. Jussi was the founder member establishing Finnish Heat Pump Association and as well founder member esta blishing European Heat pump Association (EHPA). He was also one of the members establishing Eesti Soojuspumpa Liit (ESPL) heat pump association into Estonia. Finland par ticipating IEA HPT TCP program was also consequence of Jussi Hirvonen activity.

Prof. Ruzhu Wang is full professor and the director of Institute of Refri geration and Cryogenics, Shanghai Jiao Tong University (since 1993). His institute has been recognized a world leading research institute in Refrige ration and Heat Pump Technology.

Winners of the team from Center for Environmental Energy Engineering: Dr. Reinhard Radermacher, Dr. Yunho Hwang, Dr. Vikrant Aute, Dr. Jiazhen Ling, Mr. Jan Muehlbauer.

Jussi Hirvonen, Finnish Heat Pump Association, Professor Ruzhu Wang, Shanghai Jiao Tong University and the Center for Environmental Energy Engineering (CEEE) University of Maryland were given the 2021 Rittinger Award for their efforts in the field. Center for Environmental Energy Engineering (CEEE), this team of researchers from the Center for Environmen tal Energy Engineering at the University of Maryland works on cutting-edge heat pump technology research. They have one of the world’s most comprehensive research portfolio on a wide range of heat pumping technologies both in terms of experiments and modeling. This remar kable group of researchers brings a wealth of experiences and expertise to the heat pump research community. Their contributions led to significant gains in technological deve lopment. They work collaboratively with researchers from other fields, other countries, and other institutions leading to great breakthroughs in both energy efficiency, improved performance, and reduction of manufacturing and energy costs.

10 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS

* This session included papers on a variety of non-tradi tional technologies for heat pumping systems including compression of hydrogen (keynote) and ammonia/hydro gen blends, thermoelectric (TE) cooling/heating, proton electrolyte membrane fuel cell, and a combined absorption system. The keynote speaker noted that electrochemical compression (ECC) of hydrogen likely offers the best longterm efficiency potential but is currently at a low techno logy readiness level (TRL). Using a traditional hermetic refrigerant compressor offers the best near-term potential but has efficiency limitations. TE systems offer advantages for certain applications including heat pumps for clothes dryers.

* The keynote speaker introduced the first session by tal king about that the mass market is the “next stop” for heat pumps in Europe and that the technology is on the verge of large scale deployment. He presented a qualitative assess ment of the impact of European energy and climate-based Proceedings from the 13th IEA Heat Pump Conference can be ordered from our publication database.

Reports from the Technical Sessions of the HPC2020

Two sessions were dedicated to ground source heat pump (GSHP) systems. The keynote presentation of the first session covered the development and simulation of a dual-purpose underground thermal battery with phase change material and active charging. The system allows for electricity peak shaving. The second presentation showed results from three years of performance monitoring of a GSHP system for heating and cooling, serving a Swedish mix-use building. The third paper covered a feasibility stu dy of a GSHP system for a typical residential building block in Ontario in Canada. The following presentations covered a case study on measured performance of a GSHP system in Japan, where the ground was significantly influenced by groundwater flow and a liquid natural gas (LNG) system, where the LNG was vaporized by heating it with a hybrid GSHP system, combining ground heat exchangers and air-water heat exchangers. The keynote of the second session gave an overview of the results from the first three years of IEA HPT Annex 52, which addressed long-term performance measurement of large GSHP systems. The second presentation promoted the use of a low-GWP refrigerant twin-cycle GSHP confi guration for building retrofit projects to enhance energy

The keynote described a novel system concept using a mix ture of noble gases in a rotating system; centrifugal forces compress the working fluid inside the rotating heat ex changer. Other topics were; a 600 kW industrial heat pump development effort; an experimental evaluation of a rolling piston compressor, and test results for a low-lift heat pump using an oil-free centrifugal compressor using R-1234ze(E).

» Results from multiple years of performance me asurements from six German GSHP systems for large buildings.

» Short-term storage for cooling of office buildings. Market and Policy for Heat Pumps – by Caroline Haglund Stignor

Air Conditioning and Cooling – by Van Baxter

Electrochemical Related – by Van Baxter

Ground Source Heat Pumps – by Signhild Gelin *

The keynote speaker provided an overview of India’s per spective on AC. India initiated a Cooling Action Plan (CAP) to reduce cooling energy use and refrigerant demand by 25-40% and 25-30%, respectively, over the next twenty years. The CAP also aims to train 100,000 AC technicians by 2023. The session also included several papers on im proving heat pump and AC systems for electric vehicles (EVs) and one paper stated that the EV heat pump energy consumption can be reduced by almost 19% when using battery charging reject heat as a source.

Theefficiency.following topics covered were:

New Heat Pump Technologies – by Van Baxter

VOL.39 NO 2/2021 HPT MAGAZINE 11 HEAT PUMPING TECHNOLOGIES NEWS

One of the presented papers dealt with existing “road blocks” to use of heat pumps in residential buildings for de mand response, and how to overcome them. The presen ter talked about the role of aggregators to give the end user access to the ancillary market, and about the hardware and software that is required to ensure successful implementa tion of demand response for heat pumps. Smart Applications of Heat Pumps – by Caroline Haglund Stignor * In one of the last sessions of the conference, European Heat Pump Association gave a presentation about the communication campaigns that they had shaped, aiming at a positive emotional perception of the technology while trying to achieve a high level of recognition.

The presentations in the session “Heat Pump Performan ce” reflect broad application possibilities and types of heat pumps. The following were presented: heat recovery of wa

legislation on heat pump technology. He concluded that the outlook for heat pumps is positive for three reasons: a strong market foundation, a first legislative acceleration and an expected legislative booster. In another presenta tion, the three main benefits of heat pumps were outlined – they contribute to energy efficiency, decarbonization and cost savings. However, in many countries, policies that make the polluter pay are still lacking. The price ratio electricity/gas is still a barrier in several countries. The ses sion also included a presentation about new possible bu siness models for heat pumps, which means shifting from selling boxes to selling comfort, which concluded that there is a huge opportunity for innovative ‘Heat as a Service’ mo dels to enable real growth in the heat pump market. Other topics presented were:

The session was concluded with a presentation about heat pumps for nZEBs in a Nordic climate, where comparison of field measurement data with predicted performance, based on the same calculation models that are applied in the European Ecodesign and Energy Label regulations, had been done. Heat Pumps Applications – by Marek Miara *

The two main presentation topics in the session “Space and Hot Water Heat Pumps” addressed the field performance measurement of domestic heat pumps and heat pumps in multi-family buildings. Between 1996 and 2017, more than 600 heat pump systems, mainly in single-family houses, were investigated across Europe. On average, slightly more brine to water heat pump systems were recorded than air to water heat pump systems. Although the amount of data collected over these years is important, it can only be used in part for comparison because of different definitions of key figures and system boundaries or long sampling inter vals. For drawing the correct conclusions when comparing heat pump systems, it is crucial to use the correct system limits and boundaries.

Thereafter researchers from Fraunhofer talked about a small charge heat pump with propane, with max 150 g propane and a capacity of 5-10 kW, they had built by only components available on the market.

The presentations in the session “Heat Pumps Application” mirrored the general research and development trend towards high-temperature heat pumps, heat pumps for industry and large-scale heat pumps. The primary markets for heat pumps are currently the residential, commercial and district heating/cooling markets. The penetration sta tus of industrial heat pumps is so far very low. Most indu strial heat pump applications involve the preparation of hot water for processes. As the demand for energy savings has grown in the industrial sector, so has interest in heat pumps that recycle waste heat, for example, to produce low-pressure steam. The increase in number of applications in commercial, in stitutional, and multi-family buildings makes the measu rement of long-term performance data vital. The content from IEA HPT Annex 52 is focused on this task. The results of Annex 52 show that performance vary, and we need more knowledge on the underlying causes. An important part of Annex 52 is to develop a methodology for measu rement strategies and common system boundaries for lar ger heat pump systems.

Heat Pump Performance – by Marek Miara *

» The strongly growing Finish heat pump market and the reasons behind

» An investigation about diffusion barriers and stra tegies for increase implementation of heat pump systems with integrated storage and photovoltaic in Austria.

The keynote of the second session about market and policy presented the NEDO R&D Project for Innovative Thermal Management in Japan, who relies heavily on fossil fuel and a lot of thermal energy is wasted. By use of heat pumps, a considerable amount of the wasted heat could be used, which would result in energy and CO2 savings. The ses sion also included presentations giving an overview of the US heat pump market in 2020, which has shown steady growth since 2010. Moreover, it included a techno-econo mic assessment of air-source heat pumping technologies in the Canadian residential sector, to find out under which circumstances the added investment in a variable speed or cold-climate heat pump, compared to a single-stage one, was justified.

Space and Hot Water Heat Pumps – by Marek Miara *

12 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS

Heat Transfer – by Reinhard Radermacher * This session was started with a paper presenting insightful experimental results on two-phase flow distribution in the refrigerant distributor of VRF systems. The impact of gravi ty, position of the inlet and differences between horizontal and vertical installation was discussed.

Variable Refrigerant Flow Heat Pumps and Air Conditioners – by Reinhard Radermacher *

Dehumidification Technology – by Reinhard Radermacher

ter-heating heat pumps, Hybrid HVAC System of Air Source Heat Pump and Natural Gas Furnace for Cold Climate, an air-water dual-source heat pump system for shrimp ponds, as well as a load-based testing methodology for evaluating advanced heat pump control design and a dynamic mo deling and charge minimization study of a packaged propa ne heat pump with external flow reversal for cold climates.

» An effort to increase the performance of VRF sys tems based on field test results and a machine learning-based model for better control logic deve lopment. Results show that compressor frequen cy and condenser temperature are the two most important factors affecting outdoor unit power consumption.

» A novel method to increase the durability of lubri cant-impregnated surfaces on condenser tubes.

The keynote presentation introduced the test results of a heat pump with fixed speed compressor and fan that was retrofitted with a novel electronic drive that enables the va controlriable-speedofconventionally single-speed PSC motors. The test results were very promising as both compressors and fans were operated at variable speed and could be increased to a 40% energy savings.

The last two presentations in this session covered an em pirical analysis of dehumidification performance of a hol low-fiber-membrane dehumidifier, and ionic membranes with the goal of maximizing performance and tailoring pro perties to various HVAC and Energy Recovery Ventilation (ERV) applications. Heat Pumps for Industrial Process Heat Supply

The following presentations covered the following topics and results:

» Mass transfer resistance for zeotropic mixtures during nucleate boiling on a copper surface.

» Evaporating thin film thickness is predominantly affected by the properties of the fluid, such as wet tability, and not by the droplet size.

The keynote of the session discussed the comparison of va cuum membrane dehumidification systems with moisture selective dense membrane. Simulation results were repor ted and surprisingly the version that compresses only wa ter vapor to atmospheric pressure came out to be the fa vorite. The following presentation reported another use of membranes, employing a solid-state method of humidity control based on an electrolysis cell that can either humidi fy or dehumidify. The proposed application is food preser vation, and the device is said to greatly reduce the defrost load for refrigeration applications. After this, a method and the result of a theoretical analysis of mass transfer in a va cuum membrane dehumidification system was presented.

– by Benjamin Zühlsdorf * Heat pumps for process heat supply in industrial applica tions are considered as a key technology for reducing CO2 emissions from industrial processes and are according ly the focus of various R&D activities. The IEA Heat Pump

Other topics covered were:

» A heat pump system for cooling, heating, dehumidi fication and outdoor air supply.

Advanced Controls and Modeling – by Veronika Wilk * Topics such as fault detection, power and capacity deter mination and optimized AC control was discussed in this session. The first presentation was about a convolutional neural network that was trained to detect refrigerant char ge faults and to determine the power consumption, cooling and heating capacity of an HVAC system. This was followed by a study about optimized AC control used for temperatu re control and high energy efficient pre-cooling.

Components and Cycles – by Veronika Wilk * This session addressed research and development of com ponents in order to increase the efficiency or simplify heat pumps.

The last two presentations addressed a thermal resistan ce model for the design and cost optimization of thermal storages with phase change materials and a transient buil ding performance model using Python and Modelica. * This report has been shortened by the HPC team.

14 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS

» Maldistribution of propane in brazed heat exchang ers for evaporators

exchanger during nighttime. This was followed by a pre sentation of test results of 60 existing buildings with heat pumps were analysed in a recent field test in Germany, which measured performance values of an average SPF of 3 for A/W and 3.9 of B/W heat pumps. Heat pumps thus offer large CO2 reduction potential compared to common fossil-fuel boilers.

» An expander in an absorption chiller with NH3/ water as working fluid in a combined cooling and power cycle application.

The conference will be held at Renaissance Chicago Downtown Hotel, close to the Theatre district in Chica go. The 10 Must Do’s When Visiting Chicago, the Windy City, including attractions, shopping and dining, were presented during the launch.

» Vortex tube as an alternative expansion device for high-temperature heat pumps

Brian Fricke concluded the presentation by welcoming everyone to Chicago in two years. Meet us in social media

VOL.39 NO 2/2021 HPT MAGAZINE 15 HPT TCP ANNEXES Ongoing Annexes in HPT TCP The projects within the HPT TCP are known as Annexes. Participation in an Annex is an efficient way of increasing national knowledge, both regarding the specific project objective, but also by international information exchange. Annexes operate for a limited period of time, and the objectives may vary from research to implementation of new technology. DESIGN AND INTEGRATION OF HEAT PUMPS FOR nZEB 49 AT, BE, CH, DE, NO, SE, UK, US HEAT PUMPS IN MULTI-FAMILY BUILDINGS FOR SPACE HEATING AND DHW 50 AT, CH, DE, DK, FR, IT, NL ACOUSTIC SIGNATURE OF HEAT PUMPS 51 AT, DE, DK, FR, IT, SE LONG-TERM MEASUREMENTS OF GSHP SYSTEMS PERFORMANCE IN COMMERCIAL, INSTITUTIONAL AND MULTI-FAMILY BUILDINGS 52 DE , FI, NL, NO, SE, UK, US ADVANCED TECHNOLOGIESREFRIGERATIONCOOLING/DEVELOPMENT 53 CN, DE, IT, KR, US HEAT PUMP SYSTEMS WITH LOW GWP REFRIGERANTS 54 AT, DE, FR, IT, JP, KR, SE, US COMFORT AND CLIMATE BOX 55 AT, BE, CA*, CH*, CN, DE, IT, NL, SE, TR*, UK, US INTERNET OF THINGS FOR HEAT PUMPS 56 AT, CH, DE, DK, FR, NO, SE FLEXIBILITY BY IMPLEMENTATION OF HEAT PUMPS IN MULTI-VECTOR ENERGY SYSTEMS AND THERMAL NETWORKS 57 DK, NL HIGH-TEMPERATURE HEAT PUMPS 58 AT, BE, CA, DK, DE, FR, NL, NO, JP The Technology Collaboration Programme on Heat Pumping Technologies participating countries are: Austria (AT), Belgium (BE), Canada (CA), China (CN), Denmark (DK), Finland (FI), France (FR), Germany (DE), Italy (IT), Japan (JP), the Netherlands (NL), Norway (NO), South Korea (KR), Sweden (SE), Switzerland (CH), the United Kingdom (UK), and the United States (US). Bold, red text indicates Operating Agent (Project Leader). NEW FINALIZED *) Participates from ECES TCP

HPT Annex 53 was initiated in late 2018 and focuses on the longer-term RD&D need. Technologies under investi gation include the vapor compression (VC) based systems, thermal compression-based systems (absorption and adsorption), and non-traditional cooling approaches.

ANNEX 49 DESIGN HEATINTEGRATIONANDOFPUMPSFOR nZEB 16 HPT MAGAZINE VOL.39 NO 2/2021 HPT TCP ANNEXES

Introduction It is widely acknowledged that air conditioning (AC) and refrigeration systems are responsible for a large share of worldwide energy consumption today, and this demand is expected to increase sharply over the next 50 years. IEA projects that AC energy use by 2050 will increase 4.3 times over 2013 levels for non-Organization of Economic Coordination and Development (OECD) countries and 1.3 times for OECD countries (see figure below).

» 2-page Summary Annex 49 Annex 49 has been structured into four parts that are being presented in four reports: » Annex 49 Final Report part 1: State of the Art of heat pump application in nZEB

Objectives Annex 53’s main objective is longer term R&D and infor mation sharing to push development of higher efficiency and reduced greenhouse gas (GHG) emission AC/refrige ration focused HP technologies.

The final report of Annex 49 is now published to gether with four extensive reports that are focu sing on heat pumps in nearly Zero Energy Buildings (nZEB).

> »

» Annex 49 Final Report part 4: Heat pump proto type developments and testing for nZEB applica tion

Specific areas of investigation include but are not limited to the following: » Advance the technology readiness level (TRL) of non-traditional cooling technologies and alterna tive compresson technologies to the point that forward-thinking manufacturers could be en couraged to engage in subsequent partnerships in bringing them to market; » Independent control of latent and sensible cooling and tailoring systems for different climates (e.g. hot dry or hot humid). » Advances to VC-based technologies, both conven tional and non-traditional. ADVANCEDREFRIGERATIONCOOLING/TECHNOLOGIESDEVELOPMENT53

The Annex 49 was a follow-on of the work in Annex 40 on heat pump concepts for nZEB, with an extended scope from the balance of single buildings to groups of Thebuildings.dominating concept was to reach the zero-energy balance over an annual period for nZEBs.

» Annex 49 Final Report part 3: Simulation of System integration, Design and Control for heat pumps in nZEB

» Annex 49 Final Report part 2: Field monitoring in nZEB with heat pump

Advanced VC R&D underway by participant teams inclu des a combined absorption/VC/thermal storage concept, a large chiller based on water (R-718) as refrigerant, a no vel pressure exchange (PX) concept for expansion work recovery, and enhanced source and sink stream mat ching using zeotropic refrigerants. Significant efforts are also underway aiming at advancing state of development of systems based on magneto caloric (MC), elastocaloric (EC), and electrocaloric effect (ECE) cooling cycle concepts. This includes work on identifying materials with improved fatigue performance, etc., for MC, EC, and ECE concepts.

ANNEX

Read

Final report Annex 49 Design and Integration of heat pumps for nearly Zero Energy Buildings Executive Summary Annex 49

Worldwide action, both near-term (e.g., increase deploy ment of current “best” technologies) and longer-term (RD&D to develop advanced, higher efficiency technology solutions), is urgently needed to address this challenge.

Annex 49 is sharing experiences on heat pumps in nZEB as well as design of HVAC systems for nZEB in different countries. Development and market situation of heat pump systems in nZEB has also been investi gated through this annex that was active during 2016 to 2020. Results The results from this project show that heat pumps can become the standard building technology for nearly Zero Energy Buildings (nZEB). Due to the high performance of heat pumps, nZEB can be achieved cost-effectively. Further on, heat pumps can increase on-site electricity self-consumption and unlock flexibili ty potentials by smart controls. In this way heat pumps become the backbone of a future sustainable and re newable built environment and energy system. all reports and summaries here

©2017 NAVIGANT CONSULTING, INC. ALL RIGHTS RESERVED1 (Source: IEA, Energy Technology Perspectives 2016 ) Note: Exajoule [EJ] = 1018 Joules or 0.95 Quadrillion [1015] Btus Progress highlights Italy’s Annex 53 team at CNR-ITAE is working to develop innovative adsorption cooling/heating/refrigeration sys tems. The latest research is focused to develop plastic adsorbent heat exchangers manufactured by 3D printing technique with the goal to reduce capital costs of ads orption machines and optimizing the design to fit speci fic performance. First prototypes have been developed employing the most promising polymeric materials and the performance were investigated both experimentally, to measure the dynamic performance of the new adsor ber configurations, and theoretically, to evaluate the in fluence of plastic materials on the cooling COP. Results showed that both in terms of thermodynamic and dyna mic performance the plastic adsorbers are competitive with metallic ones with a relevant mass reduction and the possibility to manufacture complex geometries (Figure 1). The potential application of plastic material and 3D prin ting manufacturing will positively impact the technical and economic feasibility of adsorption cooling technology.

Figure 1. A potential modular complex layout for plastic adsorbers [ref. Alessio Sapienza, Vincenza Brancato, Yuri Aristov, Salvatore Vasta, Plastic heat exchangers for adsorption cooling: thermodynamic and dynamic performance. Applied Thermal Engi neering, Accepted-In press]. Key data » Project duration: from January 2019 to December 2022 » Participating countries (as of 12/31/2020): China, Germany, Italy, South Korea, and USA Contact Operating Agent is Van Baxter from ORNL, USA, vdb@ornl.gov Annex website https://heatpumpingtechnologies.org/annex53/

VOL.39 NO 2/2021 HPT MAGAZINE 17 HPT TCP ANNEXES

Current and projected space cooling site energy consumption for OECD and Non-OECD countries.

Courtesy W. Goetzler, Guidehouse, Inc.; Source: IEA ETP 2016.

Publications Alessio Sapienza, Vincenza Brancato, Yuri Aristov, Salvato re Vasta, Plastic heat exchangers for adsorption cooling: thermodynamic and dynamic performance. Applied Ther mal Engineering, Accepted-In press Meetings

» The last experts web meeting took place in June 2021 in conjunction with the virtual IIR THERMAG IX Conference.

» Several Annex 53 Participants participated in a workshop of the SHC TCP Task 65 held in March. ” 3D printed plastic components could positively impact tech nical/economic feasibility of adsorption cooling technology. ”

18 HPT MAGAZINE VOL.39 NO 2/2021 HPT TCP ANNEXES

» Analysis of the LCCP impacts of the current design and optimized design with low-GWP refrigerants (planned)

1) review of the state-of-the-art technologies in HVAC components using low-GWP refrigerants, and 2) case studies and design guidelines for optimizing components and systems. As stated below, the progress achieved by the participating countries can be a valuable reference for researchers, engineers, and policymakers across the HVAC industry. It is especially interesting for people who want to dive deep into the components R&D of heat pumps, inclu ding but not limited to heat exchangers, compressors and valves. The U.S. team conducted a comprehensive review of R&D progress on components using low-GWP refrigerants for residential air conditioning applications. The review mainly focused on heat exchangers and compressors. Furthermo re, the team performed a study on tube-fin heat exchang ers' circuitry optimization. As an example, one project from the University of Maryland addressed the circuitry optimi zation of tube-fin heat exchangers, shown in Figure 1. The German team carried out several projects on heat pumps using low-GWP refrigerants. The projects covered novel components investigations, design guidelines and field testing. The Italian team conducted various R&D pro jects from academic and industry institutions. The activi ties focused primarily on developing novel components and systems for low-GWP refrigerants. Figure 2 shows a solar-assisted heat pump being installed and field-tested at the University of Padova. The French team conducted extensive investigations of low-GWP refrigerants for resi dential heat pumps, air conditioners and heat pump water heaters. A total of 10 alternative refrigerants with low-GWP were evaluated with at least 130 performance tests. These experimental results will be useful by the HVAC community

» A comprehensive review of recent R&D progress on component optimization using low-GWP refrige rants (fulfilled)

Figure 1: Optimal circuits under different constraints (a) baseline; (b) unconstrained; (c) with manufacturing (mfg) constraints; (d) with refrigerant pressure drop (DP) constraint; (e) with mfg. and refrigerant DP constraints. (Li et al., 2019) ” Significant progress has been made on designing and optimizing components using low-GWP refrigerants for heat pump applications.

» In-depth case studies of component optimization, which can provide design guidelines and real-world cases (fulfilled)

”

» An outlook for heat pumps with low-GWP refrige rant for 2030 (planned). Progress In 2020, we achieved considerable progress in the following two areas:

Objectives Annex 54 aims at promoting the application of low-GWP refrigerant to air-conditioning and heat pump systems with the following objectives:

Introduction Low-GWP refrigerants are considered long-term solutions for environmentally friendly heat pump systems. Nume rous studies have shown that design modifications are ne cessary to be optimized for low-GWP refrigerants. In parti cular, component-level design and optimizations are much needed. There hasn't been a clear picture of recent R&D progress. Further, there are not enough studies on how to optimize components and provide guidelines for various heat pump systems.

HEAT PUMP SYSTEMS WITH LOW REFRIGERANTSGWP ANNEX 54

» Optimization of heat pump systems for low-GWP refrigerants (planned)

» The fifth workshop was during IEA HPC in May 2021 and the sixth workshop was during HFO Conferen ce in June 2021.

Meetings

Figure 2: Solar-assisted heat pump prototype installed at the Solar Energy Conversion Labo ratory (Department of Industrial Engineering, University of Padova).

Key data » Project duration: Jan. 2020 to Dec. 2020

» Colombo, L.P.M., Lucchini, A., Molinaroli, L. Ex perimental analysis of the use of R1234yf and R1234ze(E) as drop-in alternatives of R134a in a water-to-water heat pump. International Journal of Refrigeration 115, 18-27, 2020.

» Hosted two online business meetings on June 24, 2020, and on December 7, 2020. During the me etings, we shared research progress from each par ticipating country and discussed the 2020 annual report preparation.

» The next workshop is planned to take place on Sep tember 1, 2021, during the IIR’s TPTPR conference.

for facilitating the selection of the most promising candi dates to replace R-410A, R-134a, and R-407C in residential heat pumps. New to the Annex last year, the Swedish team initiated several efforts on case studies and design guideli nes for component and system optimizations, particularly for Northern European climates.

Publications/Journals

» Hosted online workshop on December 7, 2020, during the 14th IIR-Gustav Lorentzen Conferen ce on Natural Refrigerants – GL2020. During the workshop, we presented natural refrigerant utili zing technologies from Japan, Germany, Italy and the U.S.

INFORMATION Welcome to the HPT TCP publications database Here you find the results of the projects implemented by the Technology Collaboration Programme on Heat Pumping Technologies, HPT TCP, and Heat Pump Centre, HPC. Do you want to read more about the results and outcome of the HPT TCP Annexes? Publication database: https://heatpumpingtechnologies.org/publications

» Li, Z., V. Aute, J. Ling, “Tube-fin heat exchanger circu itry optimization using integer permutation based genetic algorithm”, International Journal of Refrige ration 103, 135-144, 2019.

» Berto, M. Azzolin, S. Bortolin, C. Guzzardi, D. Del Col. Measurements and modelling of R455A and R452B flow boiling heat transfer inside channels. Interna tional Journal of Refrigeration, 120, 271–284, 2020.

» Participating countries: Austria, France, Germany, Italy, Japan, Korea, Sweden and the U.S. Contact Operating Agent is Yunho Hwang from the University of Maryland, College Park, USA yhhwang@umd.edu Annex website https://heatpumpingtechnologies.org/annex54/

VOL.39 NO 2/2021 HPT MAGAZINE 19 HPT TCP ANNEXES

Activities on concepts, applications and testing to be initiated Further tasks focus on the development of heat pump-ba sed solutions for process heat supply (Task 2 – Concepts) and the development of decarbonization strategies for the transition to these heat pump-based solutions considering the challenges arising from real-world installations (Task 3 – Applications). Furthermore, suitable procedures for de fining and testing performance requirements of industrial high-temperature heat pump systems will be derived (Task 4: Definition and testing of HP specifications). Tasks 2, 3 and 4 will begin during the second half of 2021. Key data » Currently, the following countries are participating: Austria, Belgium, Canada, Denmark, France, Ger many, the Netherlands, Norway and Japan.

» Task 5: Dissemination. Technology review is ongoing Task 1 will provide an overview of the current status of technologies and developments in the field of high-tempe rature heat pumps and set the direction for further work. The review includes technologies, demonstration cases and most relevant R&D projects for systems and compo nents. Task 1 will be concluded with an outlook of technolo gy development perspectives. The activities for Task 1 have recently been initiated and are currently ongoing. In addition to the ongoing review activities, there will be a range of deep dives on various focus topics. The deep dive topics are to be agreed with the Annex participants and will include contributions from various Annex participants as well as external partners.

» Task 3: Applications – Strategies for the conversion to HTHP-based process heat supply

During recent years, activities focusing on research, de velopment and demonstration of high-temperature heat pumps with supply temperatures above 100°C increased considerably. In addition to the various R&D projects, initial demonstration projects are being conducted as more and more equipment becomes commercially available.

HIGH-TEMPERATUREHEATPUMPS

» Task 1: Technologies – State of the art and ongoing developments for systems and components

Contact Operating Agent is Benjamin Zühlsdorf, from the Danish Technological Institute. bez@dti.dk Annex website https://heatpumpingtechnologies.org/annex58/

Task 2: Concepts – Development of best practices for promising application areas

Installation of a hybrid absorption/compression heat pump using a mixture of water and ammonia at Arla, Denmark Annex 58 – High Temperature Heat Pumps has been started

20 HPT MAGAZINE VOL.39 NO 2/2021 HEAT PUMPING TECHNOLOGIES NEWS ANNEX 58

» The Annex is still open for new participants, and 1012 countries are expected to participate.

Annex 58 on high-temperature heat pumps has been ini tiated to increase awareness of the technologies and their potential by providing a technology overview as well as in formation and tools facilitating the spread of the technolo gy. The Annex will provide an overview of the technological possibilities and applications and develop concepts and strategies for the transition to heat pump-based process heat supply. Activities The activities for the Annex comprise the following five tasks:

High-temperature heat pumps are a promising alternative for replacing fossil fuel-based heat supply by electrifying the processes at the highest efficiencies. The potential for industrial heat pump applications is considerable as mar ket conditions become more and more advantageous. Industrial heat pumps are expected to play a key role in industry’s transition to sustainable production processes, since the technology is driven by potentially emission-free electricity and operates at the highest efficiencies.

In general, the application potential for heat pumps in indu strial applications is great. When considering the tempera ture levels of the heating, it becomes apparent that a large share of the application potential requires supply tempera tures above 100°C, which is above the temperatures that can be supplied with state-of-the-art equipment.

» Task 4: Definition and testing of HP specifications – Recommendations for defining and testing speci fications for high-temperature heat pumps in com mercial projects

System description

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Niklas Håkansson, Xylem Sweden

Olof Andersson, Geostrata HB Sweden

Leif Rydell, Reikab AB Sweden

In 2010 Xylem, in Emmaboda, Sweden, installed a High-Temperature Borehole Thermal Energy Storage (HTBTES). The idea was to store waste heat in the summer season to use later for space heating in the winter. The system worked adequately for charging the storage, but turned out to be much less effective for extracting the stored heat. By installing a heat pump system to support heat extraction, the system now works properly both ways. This article presents the energy performance and economic s of such a system.

VOL.39 NO 2/2021 HPT MAGAZINE 21 TOPICAL ARTICLE

Introduction In 2010 an HT-BTES was put into operation at Xylem factories in Emmaboda. The storage was designed for charging 3.6 GWh of waste heat in summer, of which 2.6 GWh was estimated to be recovered for space heating the winter. In this way, a significant amount of purchased district heating was expected to be replaced (Figure 1). Until 2014 the storage was heated to around 40°C. However, during this period the storage acted perfectly as a relief for the cooling tower. Some heat was recove red during the following years, but much less than ex pected. To improve the recovery, a heat pump system was installed in 2018. The reconstructed system is now being used for performance measurements and evalua tion in IEA HPT Annex 52 (Long term performance mea surement of GSHP systems), and this article summarizes the findings after three seasons.

The storage consists of 140 boreholes, 150 m deep and with a borehole distance of 4 m. It is located just outside the factory area and has a rectangular shape measuring 60 x 40 m. On top there is a layer of sand, foam glass, and humic soil as insulation.

A coaxial type heat exchanger was developed as boreho le heat exchanger (BHE). It consists of two pipes with in termediate insulation by unmovable water. A helical spa cer was placed in each joint. An advantage of using this type of BHE is that it enables bidirectional flow. Thus, the highest storage temperature can always be at the bot tom of the storage. The use of coaxial BHE means that the heat carrier is in direct contact with the groundwater in the bedrock, approximately 3.5 m below the surface. This also means that the heat carrier must be circula ted under vacuum pressure (35 kPa) in the storage. The Figure Xylem's1.system for heat recovery from process forchasedcoolingcoolinglossesreducesofseasonalheatincludingcooling,BTESstorageforstoragewasteheat.Thisenergythroughthetowerforandpurdistrictheatspaceheating.

Heat Pump System Improved High-Temperature Borehole Thermal Energy Storage Efficiency

The storage is connected to the main technical central by a 200 m long steel culvert in which the heat carrier is circulated by using a frequency-controlled circulation pump. The pump is designed for a maximum flow rate of 21 l/s. Heat is stored into, or extracted from, the storage through a large heat exchanger. The system has sensors for instantaneous recording of temperatures, flow rate and pressure. Furthermore, the rock temperature in the storage (MW-1) and just outside is measured in two monitoring boreholes (MW-2). Also, the function of the insulation on top of the storage is measured by three temperature sensors, see Figure 2. Operational results During the first years of operation, the expected amount of waste heat with a high enough temperature was found to be insufficient. Therefore, a number of mea sures were taken to capture low-value heat sources by using heat pumps. A heat pump was installed to extract heat from the foundry's ventilation system. As a bonus, this solution also provides air conditioning for this other wise “hot” workplace. During 2014-2015, the storage temperature was stabili zed to be approximately 40-45°C even though the availa

vacuum created problems with cavitation of the circula tion pump during the first years of operation, as well as problems with degassing the fluid. These problems, and how they were solved, are described in reference [1].

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The borehole field is divided into seven sections with 20 holes in each. The three inner sections form an “inner core” intended to have the highest temperature, and the four outer sections form a “buffer zone” with a slightly lower temperature. The idea behind this design is simply to have demand-adapted temperatures at charging and discharging modes. This function is achieved by using control valves for each section, as shown in Figure 2.

bility of waste heat remained high. It became more and more obvious that instead of an increased temperature, a lateral growth of the storage took place. Hence, the storage temperature was not high enough for heat re covery by direct heat exchange only. Actually only some 10-15% of the stored heat could be recovered this way during 2015-2017. To achieve an enhanced withdrawal of heat, a heat pump system [1] was recommended. It was also recom mended to lower the working temperature of storage to a working temperature of 40/20°C. In this way, the thermal gradient should be turned towards the storage during the winter season and thus the spread sideways would cease. At the same time, the capacity using the storage for cooling would be increased by the reduced temperature. In the autumn of 2018, the heat pump system shown in Figure 2 was put into operation. The system consists of 8 parallel-connected aggregates (NIBE F1345-60). The evaporator side connects to the storage and the con denser side to the internal heating network. The evapo rator side works at the temperature 26/20°C, while the condenser side delivers a temperature up to 55°C. The system covers the heat demand down to an outdoor temperature of about -5 degrees. At lower temperatu res, the external district heating is used as backup. The high temperature of the evaporator side allows the sys tem to deliver a condenser capacity up to 800 kW. This is significantly higher than the nominal, 480 kW. As shown in Figure 3, the heat pump system has pro vided a drastically increased recovery from the storage since the start in September 2018. Consequently the storage temperature has been gradually lowered. At the end of April 2021, it was down to 28°C and still leaves a large portion of earlier stored heat to be recovered from the sides of the storage.

Figure Principal2. system flowchart with sensors for temperature (GT), pressure (GP) and energy (EM). In ad dition, electricity use for heat pumps and circulation pumps are measured. The storage tempera ture is monitored in two monitoring wells (MW) as well as in the insulation top layer.

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The use of high-efficiency borehole heat exchangers with double flow direction has not helped to obtain a long-lasting high temperature upon recovery. Such a type of BHE may instead create technical problems, such as cavitation and striping of gas, as has been experien ced in Emmaboda. Using conventional collectors (U-pi pes) is therefore recommended in order to avoid such problems. References [1] Nordell, B., Liuzzo Scorpio, A., Andersson, O. Rydell, L., Carlsson, B. 2016. “The HT BTES plant in Emma boda. Operation and experiences 2010-2015”. Div. of Architecture and Water, Luleå University of Tech nology, January 2016. Figure Accumulated3. heat reco very from the storage over the last five years. 800070006000500040003000200010000

Conclusions The HT-BTES case at Xylem showed that a heat pump system for heat recovery is needed for full recovery of stored heat. It also serves as proof that such a system in itself is highly profitable and can be operated at a high system performance factor, in this case a SPF of 4.5. The additional investment was paid off in less than three years. Hence, it is highly recommended for similar pro jects to consider using heat pumps for heat extraction already from the start.

MWh

Start of Heat Pump System

Figure 3

Table 1. Production of heat from the heat pumps and the system performan ce factor (SPF), electricity for circulation pumps included, for the heating seasons 2018/19-2020/21. Heat from (MWh)BTES Produced by HP (MWh) Electricty(MWh)used SPF (-) 5 060 6 500 1 440 4.5

OLOF GeostrataANDERSSONHB Sweden https://doi.org/10.23697/b8tt-8130olle.geothermal@hotmail.com

» Significantly higher cooling capacity during the summer, which in turn means less use of the coo ling tower and a higher COP for low-grade waste heat capture by the heat pumps.

» Reduced heat losses, modeled to be on the order of 20-30% less [1].

» Reduced cavitation risk of the storage circulation pump that works under vacuum pressure and less need for degassing the heat carrier fluid. Economics and efficiency

The investment cost of the BTES system in 2010 was approximately SEK 12 million. By replacing 2000 MWh/ year of district heating, the investment payback period was calculated as 5-6 years. However, only some 1200 MWh was recovered by the spring of 2017. This was a disappointing result. On the other hand, the investment in the storage concept led to an enhanced recovery of low-grade heat by using heat pumps. These installations were in themselves profitable by increasing the direct heat recovery to increase from 2000 up to 7000 MWh the last winter. Thus, the BTES system became a profita ble investment, even without the anticipated extraction of stored heat. Other not priced advantages have been noted. For example, the foundry got “free” climate cooling, the amount of city water for cooling in test pools declined significantly, and the operating and maintenance costs of the cooling tower decreased. The additional investment in the new heat pump system 2018 totaled SEK 2.5 million. The system has delivered 6500 MWh to the heat network during the first three winter seasons. The electricity used for the heat pumps and the circulation pumps was 1440 MWh. This means a system performance factor of 4.5 and a net saving of 5060 MWh, (78%). For Xylem this is worth about SEK 3.8 million, which means that the additional investment pay back took place after just 2 years.

The lowered storage temperature also brings several other advantages:

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Integral Design: A focus on an integrated set of physical components and controls, in a similar manner to cur rent generation heat pump systems. This supports ease of installation and commissioning, and better ensures consistent performance.

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Heat pump and thermal storage systems can support an increased adoption of heat pumps by providing a more flexible link between the building and electrical grid. This article explores the development of these systems from a Canadian perspective, outlining key design requirements, presenting potential system solutions, and examining demand reduction potential through initial simulations. Findings provide an important basis for ongoing research to better adapt these systems to the Canadian climate and market.

Exploring Storage Options: Thermal Storage for Ca nadian Homes Selecting a target for the energy storage capacity of the system is a critical design decision, influencing size, cost and load shifting potential. In this study, sizing is based on covering the maximum thermal demands of the buil ding for a 2H peak event occurring during either mor ning (6 AM – 9 AM) or evening (4 PM – 8 PM) hours. For a typical new construction home in Montreal, this equates to a required storage capacity of 15 kWh. However, gi ven variations in climate and housing size/construction, a flexible approach is likely required in Canada to adapt capacity to the context of the actual installation.

Compactness: An emphasis on minimizing storage size, as Canadian homeowners and builders typically place a high value on maximizing livable area, at the expense of added space for mechanical systems. Prioritizing com pactness is particularly important for the retrofit market, where system installation must be designed around ex isting constraints.

Heat Pumps and Thermal Storage: Canadian Perspectives

As the world transitions towards a decarbonized eco nomy and infrastructure, efficient renewable energy technologies are of great importance. Canada’s Market Transformation Roadmap [1] presents a framework for the increased adoption of these systems, outlining aspi rational goals regarding system performance (seasonal heating efficiency >100%) and the integration of renewa ble energy. Heat pumps respond well to these objecti ves, but their widespread adoption can be challenging for electrical utilities. Despite their energy savings potential, heat pump use coincident with other electrical end uses can increase house-level electrical demand. This increased demand can be particularly problematic for utilities when it oc curs with a high degree of simultaneity (i.e., for many ho mes in a given region at the same time). Air-source heat pumps are a popular choice of heat pump integration in Canada, but can be especially problematic in this context. These systems tend to experience capacity degradations at colder outdoor temperatures, necessitating the use of supplemental electrical resistance heating. Given the link to outdoor temperatures, this tends to occur with a high degree of simultaneity across a given region [2], creating larger aggregated loads. This added electrical demand can challenge the generating capacity of the grid, imposing practical limits on heat pump adoption. Furthermore, in regions where electrically based heating is already common, it also presents a challenging busi ness case for utilities, as heat pumps may reduce overall electricity use but still account for large peak demands. Despite these challenges, heat pumps can also be an im portant tool in supporting more energy-flexible electrici ty grids. Integrating heat pumps with thermal storage can provide a flexible link between the thermal and electri cal networks of the building, allowing the heat pump to adapt its operations to the needs of the grid without sacrificing thermal comfort. This article explores Natural Resources Canada’s ongoing research on air-source heat pump and thermal storage systems, providing Canadian perspectives on design requirements and system solu tions in line with contributions to IEA HPT Annex 55. System Design: Requirements and Design Objectives Annex 55 outlines nine key quality criteria to structure the discussion on heat pump and storage systems. Whi le criteria such as affordability and customer apprecia tion are clearly important, from a technical perspective, Canadian work has focussed on addressing three criteria: Suitability: An emphasis on air-based distribution (com mon in Canadian homes), supplying both heating and cooling (growing demand for cooling), and maintaining strong cold climate performance (to reduce electrical peaks associated with activation of electric resistance auxiliaries).

Justin Tamasauskas, Arash Bastani, Canada

Figure 3 compares the electrical demand during peak hours for three space-heating systems: Electric basebo ards (Elec. BB), a variable capacity heat pump without storage (VCHP), and a variable capacity heat pump with storage (VCHP + Storage). While the VCHP (without stora ge) greatly reduces electrical demand for 99% of opera ting hours vs. electric baseboards, maximum demand for the two systems is similar. During the coldest win ter periods, outdoor temperatures fall below the mini mum operating temperature for the selected heat pump (TOutdoor <-25°C). The VCHP is therefore unavailable to operate and auxiliary resistance elements must be used to provide space heating, increasing demand. This ope ration clearly poses a challenging business case for grid operators, who may sell less electricity but still be requi red to maintain infrastructure for the worst-case peak. On the other hand, the VCHP + Storage case appears to offer meaningful demand reductions vs. both systems throughout the operational window, primarily because auxiliary resistance heating can be offset through the Itstorage.isimportant to note that these results are highly spe cific to the case examined. The ability of the system to displace electrical demand is closely tied to whether the heat pump is able to charge the storage during off-pe ak hours. Should the building thermal load remain high during these periods, the system may have limited abili ty to charge, reducing the magnitude of demand reduc tions obtained. This impact may potentially be mitigated Material selection also has an impact on the physical size of the thermal storage. Given the emphasis on compact ness, phase change materials (PCMs) are of particular in terest in the Canadian context. An initial analysis shows that, by using commercially available PCMs with phase change temperatures of 40-45°C, storage volumes can be reduced by as much as 60% (vs. water-based storage, temperature rise 15°C). These reductions show the po tential benefits of using PCMs, although final material se lection must consider additional factors, including ther mal conductivity, chemical stability, and relative price.

The way in which thermal storage is integrated with the heat pump has important implications for the perfor mance, energy flexibility potential, and suitability of the system. For the Canadian systems examined in Annex 55, the heat pump and storage system consists of three main components: an outdoor unit (Refrigerant - Out door Air HX and Compressor), indoor unit (Refrigerant - Indoor Air HX), and thermal storage unit (Refrigerant - PCM heat exchanger and fan). Despite the relative simplicity of this component list, system performance is closely tied to the way in which these components are Figureconfigured.1shows

gree of space heating, without the need to operate the heat pump compressor. One major challenge in designing heat pump and stora ge systems is ensuring sufficient charging times. Heat pump and storage systems may be required to respond to multiple peak periods during the same day (e.g., mor ning and evening events), necessitating sufficiently fast charging during off-peak hours. These charging times are closely related to the amount of heat pump capa city dedicated to charging (i.e., whether the storage can be charged using the full, or partial, capacity of the heat Figurepump).2 examines the impact of part load on idealized charging times, tabulated using a simple heat pump cycle model of a two-ton air-source heat pump. Results clearly show that, in order to sufficiently charge between morning and evening peak periods, systems would need to charge above 70%-part load.

Enhancing the Energy Flexibility of Canadian Homes: A Building-level Analysis A simulation-based approach is used to illustrate the performance of these systems in a newly constructed single-family home in Montreal, Canada. The studied heat pump and storage system follows the configuration outlined in Figure 1, and is operated to avoid compres sor operation during peak periods. During these times, the storage unit is used to directly heat room air. Char ging occurs during off-peak hours, when the heat pump is operating below its maximum capacity.

UnitOutdoor

ExpansionPressureValve

Flow Regulating Valve Storage Unit Indoor Unit

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Integrating Heat Pump and Thermal Storage: A Cycle-Level Analysis

one configuration examined under Cana da’s contribution to Annex 55, suitable for both ducted and ductless air-to-air heat pumps. The concept uses excess thermal energy stored during off-peak hours to directly heat the building, avoiding heat pump com pressor use during peak periods. Energy is added to the storage unit (i.e., charged) by using the storage as an ad ditional condenser. During off-peak hours, a portion of refrigerant exiting the compressor passes to the storage unit. Here, the refrigerant passes through a series of pi pes surrounded by a storage material, allowing a direct refrigerant-storage heat exchange without the need for secondary heat transfer fluids. During peak periods, energy may be removed from the storage unit (i.e., discharged) by passing room air over the surface of the storage via a fan. This provides a de Figure 1: Diagram of a Heat Pump and Storage Con cept High Pressure Low

Conclusions and Future Work

Heat pump and thermal storage systems can impro ve the interaction between the building and electrical network by allowing heat pumps to adapt their opera tions according to grid needs without sacrificing thermal comfort. This ability positions heat pumps as a key tool to support future smart grids, thus facilitating a more wi despread adoption of heat pumps and renewable energy systems. However, these systems must be well adapted to their target market. This article has examined the de velopment of air-source heat pump and storage systems from a Canadian perspective, tracing how design requi rements impact system solutions, and examining poten tial demand reductions in Canadian residential buildings. This article presents initial results from an ongoing pro ject exploring heat pump and thermal storage systems in Canada. Recent work has focussed on enhanced mo deling to better assess energy transfer rates to/from the storage, and support the examination of additional system configurations. Simulation work will also be ex JUSTIN ResearchTAMASAUSKASEngineer Canada https://doi.org/10.23697/sa3c-sr82Justin.Tamasauskas@canada.ca

Figure Impact3:of heat pump and stora ge on homele-familydemandelectricalinasingCanadian

References [1] Natural Resources Canada, 2017. Paving the Road to 2030 and Beyond: Market transformation road map for energy efficient equipment in the building sector. Govt. of Canada, Ottawa, CA. [2] Protopapadaki C., Saelens D., 2017. Heat pump and PV impact on residential low-voltage distribution grids as a function of building and district proper ties. Applied Energy 192, p. 268-281. by selecting a larger capacity heat pump, or by taking ad vantage of the additional thermal storage inherent in the building mass. Regardless, it is clear that system sizing and integration is a critical issue that must be addressed to capitalize on the potential of these systems.

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Figure Impact2:of Part Load on Charge Times

panded to further assess performance in other buildings and regions in Canada. Experimental activities are also planned to provide a practical understanding of perfor mance in the Canadian climate.

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We have reviewed various configurations presented in the literature, in both active and passive storage, and analyzed the reported demand impact, energy savings, and cost s avings. Sara Sultan, Kyle R. Gluesenkamp, United States

Thermalissues.Energy

The State of Art of Heat-Pump integrated Thermal Energy Storage for Demand Response

Morepotential.than 44% of the houses in the U.S. were built be fore 1970 [3] based on outdated building codes. Typi cally, in US residential buildings, there is no mechanical outdoor air exchange, or cross ventilation using natural resources, therefore, heat pumps are important to regu late the humidity inside the house as well as the indoor temperature. Thus, retrofit technologies are needed for a rapid transition to heat pump integrated storage. It is often cost-prohibitive to rebuild houses or update the conventional air conditioning methods, but heat pump systems can be made smart to respond to peak demand. Today’s high-efficiency HVAC and appliance products can provide energy savings, but do not generally help with demand management and grid stress. Thermal energy storage can provide benefits when integrated with the heat pump components. TES ma terials can be charged and discharged to store and re lease energy, respectively, thus reducing the time and shifting heating or cooling energy demand. Despite di urnal changes in outdoor temperatures, the high-ther mal-mass buildings can maintain inside temperature in a comfortable range without expending an excessive amount of HVAC energy. Path Forward This article summarizes the state of art of heat pumps integrated with thermal energy storage. Phase change materials (PCMs) are thermal storage materials that can be embedded into heat pump equipment or building en velope. Research has explored a wide variety of methods to incorporate PCM into systems for space heating and cooling, in both active and passive storage, as well as be ing incorporated into buildings using various configura Thetions.majority of the existing commercial PCMs are incor porated in passive storage and they charge and dischar ge depending on the ambient temperature. In passive storage, PCM can be installed in the building envelope such as walls, ceiling, windows, or embedded directly into the building material such as concrete. Ideally, the materials in passive configuration can offset the peak demand by shifting loads, but they are unable to control the charging or discharging operation to optimize grid Activebenefits.TES systems on the other hand use mechanical work to transfer heat between the space and the PCM, hence there is some control over when the TES system is charged and discharged. Examples of this setup are a standalone storage tank system with an integrated heat exchanger coupled to the building’s ventilation system or a vapor compression system. The TES system may be separate and removed from the space. One advantage of these active configurations is the ability to add these systems to existing building infrastructure without signi ficant construction. For grid-interactive buildings, a demand response stra tegy can be designed for building load and grid stress management. The utility providers may define peak hours and off-peak hours of operations based on a Download and share this article

Introduction Buildings are responsible for about 40% of the total en ergy consumed in the U.S. [1], accounting for 75% of the total electricity consumption, and 78% of the 2–8 PM peak period electricity use [2]. Heating, ventilation, and air conditioning (HVAC) loads account for nearly half of the building electricity consumption and exacerbate de mand Storage (TES) has been identified as a key enabler to reduce peak energy demands and grid stress through demand response strategies as described in the Department of Energy’s Grid-Interactive Efficient Buildings (GEB) report [2]. TES may even allow refrigera tion or HVAC systems to operate during outages, though this requires larger storage capacities than a system strictly intended for diurnal load shifting [2]. TES technology with greater flexibility presents research and development opportunities in materials, configura tions, and controls: novel TES materials can be develo ped to increase energy storage density, many configura tions can be explored to reduce installation complexities and TES footprint, and TES operation can be optimized through controls for demand response in grid-interactive buildings to offer greater energy and demand reduction

Heat pump integrated thermal energy storage is analyzed for demand response in grid-interactive buildings.

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There is a large variation in the benefits provided by TES depending mainly on the system configuration, TES location, and TES type. Peak load reduction ranges from 12% to 57%, and electricity consumption savings ranged from 9% to 62%. In this work, we have tried to present a comprehensive review of various heat pump integrated PCM-based TES configurations with a demand impact and economic analysis. The thermal energy storage systems (TES) incorpora tion with current cooling, heating, and ventilation sys tems has been shown to shift the load and energy use of the HVAC systems from on-peak to off-peak times to bypass the peak charges due to high demand. TES has also been shown to improve energy efficiency by con trolling the energy supply and energy demand gaps. Ac tive heat pump integrated TES configurations generally outperform passive TES-HP configurations because acti pre-determined schedule or a high demand-based char ge schedule. During the time of high demand or peak hours, the utility rate tends to be higher than what is nor mally charged to customers during normal or off-peak hours. Load shifting can manage the demand by shifting peak load to off-peak or normal operating hours, hence reducing the utility cost and grid stress. When properly controlled, thermal storage can be useful in an economic or behavioral curtailment scenario for demand response. Major factors influencing an appro priate TES system's choice include the energy storage period and duration, cost and economic feasibility, and operational conditions. The key to using this technology to provide grid benefits is the development of materials or packaging in an active storage configuration that al lows real-time control of the charging and discharging processes for grid-interactive operation. The energy sa vings and grid benefits in such configurations would be particularly significant in regions of high peak demand The[2].

The active configurations reported here are the ones integrated with air conditioning or heat pumps. Most researchers have commonly used a standalone storage tank containing a PCM and heat exchanger, while others have incorporated PCM into heat pump system compo nents like the supply and return air ducts, and evapo rator. Another common practice is to use two storage tanks for both cold and heat dissipation (see 7a and 7b in the figure).

Figure 1: Ten ways to integrate TES with heat pump were identified in the literature, as summarized here. with embedded TES in various possible configurations. Some are used in passive configurations and installed in building envelopes like frame walls, ceilings, floorboards, and attic insulation. The passive configurations included are connected to the air conditioning system and the ef fect of air conditioning load reduction is studied.

use of phase change materials as TES has its advan tages reported in the literature. Researchers have used various demand management systems to take advanta ge of lower utility rates during the off-peak hours and used TES in various configurations for storing the energy to be used later during peak hours, as shown in Table 1 and Figure 1. A selection of ten references is shown here to represent the state of art available in the literature, with one re ference chosen to represent each configuration type. The figure shows building and heat pump components

TES has been shown to reduce building energy consump tion from 9% to 62% and building peak load from 12% to Heat57%. pump integrated TES allows the use of already esta blished technology and resources, with minimal equip ment that can reduce the installation complexity. Heat pump-integrated TES equipment is also programmable with the thermostat for demand response and can pro vide building flexibility. With the number of possibilities, novel configurations can be explored that offer maxi mum benefits to both consumer and grid, while minimi zing the TES footprint. Research is needed in controls to optimize performance under various utility tariffs for demand response as well as develop novel directly coupled configurations to redu ce the TES footprint.

savings 3-4

Abu-Hamdeh et al., 2021 Passive In frame wall of airconditioned building energy savings Air handling unit’s power usage decreased by 11.73% years payback

Zhu et al., 2011 Passive In the walls to enhance envelope of air-conditioned PCM building Daily electric consumption reduced by 10% peak demand Barzin et al., 2015b Passive In wallboard with underfloor heating 44.4% energy hr of Peak load shifted cost

Table 1: The ten representative heat pump integrated configurations included here have been shown to reduce peak load by 12% to 57%. *Calculated based on the data provided in the paper

11%reductioncostreduced

11.25%

Reference Configuration TES Location Outcomes

savings

17-20%

Hirmiz et al., 2019 Active Integrated with heat pump via condenser storage tank 6 hr Load shift

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Challenges and Future Work

Halford et al., 2007 Passive Modeled to be installed in the attic 19 - 57% peak load reduced

Chaiyat, 2015 Active In the return air duct coupled with evaporator Cooling load decreased by 3.09 4.159.1%kWh/dcostsaved,yearspayback

The HVAC system incorporating TES is beneficial to both residential and commercial buildings by providing grid value, though the residential system requires more in stallation costs making it challenging for many consu mers to adopt this technology. The end-user would need to purchase the equipment for new construction, repla cement of an old heating/cooling system, or retrofit app lications. The most financially motivated users tend to be the consumers paying demand charges or on tariffs like Time-Of-Use (TOU) rates, as TES is ideal to shift the predictable daily load for demand response. The perfor mance of active TES systems can be optimized by taking advantage of favorable environmental conditions and pre-scheduled utility tariffs to charge the storage medi um efficiently. However, careful scheduling is required to maximize the benefit to avoid round-trip energy losses.

35%

Bruno et al., 2014 Active In chiller used as evaporator 13% cooling energy savings Takeda et al., 2004 Active In supply air duct of ventilation system 42.8 to 62.8% ventilation load reduced Kondo et al., 2006 Active In ceiling board coupled with air handling unit 9.4% load reduction

18.6

Dong et al., 2019 Active Direct coupling with the electrical heat pump via storage tanks 13% power savings 12.7% peak load shifted* 19% electricity cost savings ve storage systems offer a high level of control of indoor conditions and improve heat energy storage. A particularly promising configuration is the directly cou pled active TES-HP configuration by Dong et al., which re quires small modification and offers large performance improvement while reducing the TES footprint.

Conclusions This article reviews the state of art of heat pump inte grated TES in grid-interactive buildings. Various configu rations are reviewed and active storage is found to be more beneficial for daily load shifting, where PCMs can be charged for generation during off-peak hours.

KYLE R. GLUESENKAMP Senior R&D Scientist United States of America

[5] N. Zhu, S. Wang, Z. Ma, and Y. Sun, “Energy perfor mance and optimal control of air-conditioned buil dings with envelopes enhanced by phase change materials,” Energy Convers. Manag., vol. 52, no. 10, pp. 3197–3205, Sep. 2011

[3] M. Sarkar, “How American Homes Vary By the Year They Were Built; How American Homes Vary By the Year They Were Built,” Washington, DC, 2011. Acces sed: May 20, 2021. http://www.census.gov/const/ www/charindex.html.

Save the date – IEA HPT TCP National Experts meeting 2021, October 28, Nuremberg INFORMATION

[4] C. K. Halford and R. F. Boehm, “Modeling of phase change material peak load shifting,” Energy Build., vol. 39, no. 3, pp. 298–305, Mar. 2007

References [1] U.S. EIA, “Annual Energy Outlook 2020,” 2020. Acces sed: Apr. 20, 2020 [2] B. Goetzler, M. Guernsey, and T. Kassuga, “Grid-in teractive Efficient Buildings Technical Report Series: Heating, Ventilation, and Air Conditioning (HVAC); Water Heating; Appliances; and Refrigeration,” 2019.

[6] R. Barzin, J. J. J. Chen, B. R. Young, and M. M. Farid, “Application of PCM underfloor heating in combina tion with PCM wallboards for space heating using price based control system,” Appl. Energy, vol. 148, pp. 39–48, Jun. 2015 [7] N. H. Abu-Hamdeh, A. A. Melaibari, T. S. Alquthami, A. Khoshaim, H. F. Oztop, and A. Karimipour, “Effica cy of incorporating PCM into the building envelope on the energy saving and AHU power usage in win ter,” Sustain. Energy Technol. Assessments, vol. 43, p. 100969, Feb. 2021 [8] F. Bruno, N. H. S. Tay, and M. Belusko, “Minimising energy usage for domestic cooling with off-peak PCM storage,” Energy Build., vol. 76, pp. 347–353, Jun. 2014 [9] S. Takeda, K. Nagano, T. Mochida, and K. Shimakura, “Development of a ventilation system utilizing ther mal energy storage for granules containing phase change material,” Sol. Energy, vol. 77, no. 3, pp. 329–338, Sep. 2004 [10] T. Kondo and T. Ibamoto, “Research on thermal storage using rock wool phase-change material ce iling board,” in ASHRAE Transactions, 2006, vol. 112 PART 1, pp. 526–531. [11] N. Chaiyat, “Energy and economic analysis of a buil ding air-conditioner with a phase change material (PCM),” Energy Convers. Manag., vol. 94, pp. 150–158, 2015 [12] R. Hirmiz, H. M. Teamah, M. F. Lightstone, and J. S. Cotton, “Performance of heat pump integrated pha se change material thermal storage for electric load shifting in building demand side management,” En ergy Build., vol. 190, pp. 103–118, May 2019 [13] J. Dong, B. Shen, J. Munk, K. R. Gluesenkamp, T. Laclair, and T. Kuruganti, “Novel PCM Integration with Electrical Heat Pump for Demand Response,” 2019

The Technology Collaboration Programme on Heat Pumping Technologies (HPT TCP) by IEA will organize a National Experts meeting on October 28, 09.00-16.30, in Nuremberg, Germany, in con junction with the European Heat Pump Summit , which will take place on October 26-27 in the same location. The main purpose with the meeting is to develop new ideas and proposals for future Annexes (in ternational collaboration projects) within the HPT TCP. Examples of topics to be discussed during the meeting is how to stimulate mass deployment of heat pumping technologies, how to improve the affordability, how to explore the flexibility potenti al, how to integrate with other renewable techno logies and which measures to be taken to extend the use of both the cold and the warm side of the Youcycle.are welcome to participate and to invite other researchers and industry representatives from your country! Please register for the meeting on September 15 as the latest. If you have ideas or proposals for new annexes that you want to discuss during the meeting, please in form us by sending an e-mail and we will take that into consideration when outlining the agenda for the meeting. Read more >

https://doi.org/10.23697/62tr-nt79gluesenkampk@ornl.gov

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8 10 12 2 4 6 8 10 12

Beforeresponsive.implementing the grid-responsive load shifting measures, it is necessary to simulate the impact on peak power reduction, energy and utility cost savings, and comfort levels in template buildings over a wide range of climate conditions. EnergyPlus is a whole-building energy simulation engine developed by the U.S. Department of Energy. This study aims to utilize and improve EnergyPlus to simulate grid-responsive, flexible HVAC (heating, venti lation, air conditioning) cooling measures.

A grid signal can represent any variations related to the power grid. Figure 1 depicts hourly electricity prices (cents) in the summer (cooling season). This is the typical pricing pattern in the cooling season based on average prices for January 2016 through December 2019 provi ded by the ComEd Company, the sole electric provider in Chicago and much of Northern Illinois. The grid signal can be described using the EnergyPlus feature of Sche dule: Compact. Grid-Responsive Multi-Mode Coil Collection with Ice/ PCM Storage During a grid-responsive period, a cooling coil may be required to run at a reduced capacity than what is requi red by the building load. It may operate differently from its normal mode, for example, reduce the air flow ratio

Indoor

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This study uses EnergyPlus building energy simulations to assess grid-responsive HVAC cooling measures during peak hours having high electricity prices, including: lock the high capacity of a two-speed cooling coil during grid-response hours; and use ice/PCM energy storage to drive a chilled water coil and meet the cooling load, when shut off the main electric cooling coil. The impacts on peak power reductions, energy and utility cost sa vings, as well as comfort levels in residential buildings of tw o U.S. cities, were revealed.

Simulations of Grid-Responsive HVAC Cooling Measures via Ice/PCM storage

Summer Fall, Winter, Spring

coolingDXcoil

Figure 1: Grid signals (hourly electricity prices) represented by a schedule. Figure 2: System configuration of a variable-speed DX cooling coil integrated with an ice/PCM energy storage, water cooling coil and an air source chiller. Chilledwatercoilair Indoor air Indoor air Ice/PCMstorgetank sourceAirchiller kWhperprice 4 6 A.M. A.M. A.M. A.M. A.M. P.M. P.M. P.M. P.M. P.M. P.M. A.M. Download and share this article

Energyplus grid-responsive cooling GridmeasuresSignalSchedule

Bo Shen, Oak Ridge National Laboratory, USA Grid response involves strategically shifting demand for electric power to avoid overloading the grid during peak demand. The effect of demand response is usually refer red to as “peak shaving” and “valley filling”. Over the past decade, a number of control strategy and scheduling planning methods have been developed to address the demand response problem of DX (direct expansion) cooling systems. For example, cooling sys tem energy costs can be reduced using thermal storage in building mass, or ice storge/phase change material (PCM) storage. Very few studies are available addressing how to achieve grid response by directly modulating the speed of compressor. Compared with other strategies, such as regulating the set-point temperature of smart thermostat and scheduling the heat pump to periodical ly start up and shut down, modulating the compressor speed does not require a balance period between buil ding load and cooling capacity, and therefore is highly

The multi-functional unit used in the simulation is ba sed upon the EnergyPlus air-source Integrated Heat Pump (IHP). The IHP object was expanded to include a variable-speed air-source chiller, which charges an ice/ PCM storage tank defined in the IHP. The configuration of integrating a DX cooling coil with supplemental chilled water coil, ice/PCM storage tank and an air-source chiller to charge the tank is given in Figure 2.

60555045403530 0 2 4 6 8 10 12 14 16 18 20 22 24 [%]HumidityRelative Time [hour] Baseline Low Stage w Reduced Air Flow Low Stage w Normal Air Flow 28,527,526,525,524,523,52425262728 0 2 4 6 8 10 12 14 16 18 20 22 24 [C]TemperatureZone Time [hour] Baseline Low Stage w Reduced Air Flow Low Stage w Normal Air Flow

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10 cents/kwh, which roughly covers the period from 12 pm to 6 pm in each cooling day. Limit high capacity of modulating cooling coil with/ without enhanced dehumidification A two-speed DX cooling coil in each home was auto-si zed to match the building design cooling load at the high speed. The low speed has approximately 75% capacity of the high speed. In the two cities, we conducted annual si mulations, comparing three scenarios: 1) the DX cooling coil to match the building load as needed, without a grid response (baseline); 2) turn on a grid responsive control to only run the compressor low speed with its normal air flow rate, during the specified grid-responsive hours (modulating with normal flow); 3) use a grid responsive control with enhanced dehumidification, i.e. running the compressor at a low speed with 50% reduced indoor air flow rate (enhanced dehumidification). Figures 3 and 4 below illustrate a controlled zone temperature and rela tive humidity during a peak cooling day in Atlanta. After locking the top capacity, neither the operation at the low speed with normal air flow nor with enhanced dehumidi fication can meet the zone sensible load, which resulted in lost control of the zone temperature. The option with enhanced dehumidification resulted in the highest im pact on the temperature because of its smaller capacity. On the other hand, this option controlled the indoor re lative humidity below 40%. relative to its delivered capacity, and thus the moisture removal may be enhanced for better comfort level. We need to incorporate multi-mode cooling coils with capa city modulation and enhanced dehumidification.

Figure 4: Controlled zone relative midity during a peak cooling day.

Figure Controlled zone temperature during a peak cooling day.

We selected single-family homes with slab foundations in Atlanta, Georgia (representing a typical southern cli mate), and Indianapolis, Indiana (representing a typical northern climate), to assess the grid-responsive cooling measures via building annual energy simulations. The single-family homes were from the EnergyPlus library of template buildings. They were built according to the IECC (International Energy Conservation Code) 2006 energy code specific to individual climate zones. The cooling set point is 23.3°C throughout the year. To assess the grid-responsive cooling measures, we fol low the grid schedule in Figure 1, and start a grid-respon sive operation when the hourly electricity price is above

Building Energy Simulations

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Table 2 shows the annual energy simulation results from Indianapolis. The trends are the same as Atlanta, except with more uncomfortable hours with the indoor air tem peratures >27°C and relative humidity >50%. Ice/PCM Storage When coupled with an ice/PCM storage as shown in Figu re 2, the compressor is turned off during grid-responsive hours, while running the air flow rate corresponding to the high (nominal) compressor speed. The storage tank drives the chilled water coil to provide supplemental cooling. The water coil supply air temperature is control led at 13.0°C.

The air-source chiller was auto-sized together with the DX cooling coil to maintain a constant ratio between the rated capacities. When the solid ice/PCM fraction is below 90%, it calls the chiller to start charging until the fraction reaches above 99%. The chiller is only allowed to run when the electricity price is below 10 cents, i.e., during non-grid-responsive hours. To simplify the analyses, it is assumed that the ice stora ge tank has a constant exit temperature of -0.5°C to the chiller during charging, and 7.2°C to the water coil during discharging. The PCM storage tank has an exit tempera ture of 4.5°C to the chiller during charging and 10.0°C to the water coil during discharging. The PCM has an onset phase change temperature of 5°C and termination tem perature of 6°C. The heat transfer UAs (U = overall heat transfer coefficient, A = heat transfer area) are auto-sized to satisfy the temperature settings.

Table 1 shows the annual energy simulation results from Atlanta. The total cooling energy delivered is identical among the three scenarios. Generally, a cooling coil is si zed to match the building’s maximum cooling load at the peak ambient temperature in the climate zone. Therefo re, the low-speed operation (75% capacity) is still able to satisfy the building load on most occasions except a small range around the highest ambient temperature. During the grid-responsive hours, the zone temperature increa ses due to top capacity locking. After the grid-responsive period, the DX cooling unit recovered the zone air and envelope to the original setting temperature. Consequ ently, the grid responses did not reduce the total cooling demand noticeably. Due to the reduced indoor air flow rate, the enhanced dehumidification causes lower seaso nal cooling COP, i.e., 4.16 versus 4.57 of the baseline. As a result, the enhanced dehumidification leads to more seasonal electricity consumption and higher electricity costs. Limiting the top cooling capacity did not reduce the electricity cost, but resulted in a 26–28% peak power reduction. Both the modulating with normal flow and enhanced dehumidification maintained the zone tempe rature below 27°C and relative humidity below 50%, i.e., with minor impact on the comfort level.

COP. Atlanta DeliveryCooling Electricity consumption Seasonal COP Price Un-comforthours Peak Power Reduction Unit kwh kwh W/W USD > 27°C, 50% RH % Baseline 11069.8 2423.0 4.57 251.1 0 0 Modulating w Normal flow 10957.1 2381.1 4.60 246.1 0 26% dehumidificationEnhanced 11187.2 2691.2 4.16 281.9 0 28% Indianapolis DeliveryCooling Electricity consumption Seasonal COP Price Un-comforthours Peak Power Reduction Unit kwh kwh W/W USD > 27°C, 50% RH % Baseline 8351.5 1797.5 4.66 191.7 0.0 0% Modulating w Normal flow 8205.3 1741.8 4.72 184.7 6.0 27% dehumidificationEnhanced 8346.4 1954.5 4.28 209.0 12.0 28% Table 1: Cooling seasonal energy simulations in Atlanta, with locking high speed during grid-responsive hours. Table 2: Cooling seasonal energy simulations in Indianapolis, with locking high speed during grid-responsive hours.

Table 3 presents cooling energy simulation results when coupled with ice storage and PCM storage in Atlanta. During the grid-responsive hours, the ice/PCM cooling storage drove the water coil to meet the zone load. The total cooling energy delivered and total electrici ty consumption contains the energy from both the DX cooling coil and the air source chiller during non-grid-re sponsive hours. It can be seen that the chiller delivered capacity to the storage tank, amounting to 70% of the total cooling energy delivered, because the grid-respon sive periods involve the major cooling load. Although the energy consumptions of ice and PCM storages are higher than the baseline, their seasonal electricity price are lower, since the charging operations use low-cost electricity in off-peak hours. The electricity consumption and cost of the PCM storage is lower than the ice storage because the PCM storage corresponds to higher coolant charging temperature, which elevates the chiller

34 HPT MAGAZINE VOL.39 NO 2/2021 TOPICAL ARTICLE BO OakSHENRidge National Laboratory United States of America https://doi.org/10.23697/z1jv-1x76shenb@ornl.gov Table 4 presents cooling energy simulation results when coupled with ice storage and PCM storage in Indianapo lis. It indicates the same trends as for Atlanta. Conclusions The EnergyPlus building energy simulations imply that locking the high capacity of a modulating, cooling coil, from 100% to 75% during the grid-response hours, can effectively reduce the peak power consumption up to 28%. The strategy impairs the comfort level only to a mi nor extent. Enhanced dehumidification at the low speed is able to reduce the indoor relative humidity at the ex pense of lower cooling efficiency. Ice/PCM storages cou pled with a DX cooling coil are able to eliminate nearly all the peak power consumption, excluding the indoor fan power. They result in lower electricity bills due to mainly using low-cost electricity during off-peak hours. References [1] ComEd Company, typical pricing pattern in cooling season based on average prices for January 2016 through December https://hourlypricing.comed.com/live-prices/2019, [2] U.S. Department of Energy, EnergyPlus, https://energyplus.net/ Visit our website of the Technology Collaboration Programme on Heat Pumping Technologies (HPT TCP) by IEA. heatpumpingtechnologies.org INFORMATION TotalDeliveryCooling Total Electricity consumption Total Seasonal COP Price DeliveryChiller Chiller Electricity Consumption ChillerCOP kwh kwh W/W USD kwh kwh W/W Baseline 11069.8 2423.0 4.57 251.1 0 0 0 Ice Storage 11004.1 2830.0 3.90 191.9 7842.0 2189.3 3.6 StoragePCM 10806.7 2523.6 4.28 175.0 7634.2 1881.8 4.1 TotalDeliveryCooling Total Electricity consumption Total Seasonal COP Price DeliveryChiller Chiller Electrici ty Consumption ChillerCOP kwh kwh W/W USD kwh kwh W/W Baseline 8351.6 1797.6 4.66 191.7 0 0 0 Ice Storage 8526.6 2156.2 3.96 150.1 6313.6 1715.8 3.7 StoragePCM 8374.9 1921.9 4.37 137.1 6155.5 1481.1 4.2 Table 3: Cooling seasonal energy simulations in Atlanta, coupled with ice/PCM energy storage. Table 4: Cooling seasonal energy simulations in Indianapolis, coupled with ice/PCM energy storage.

VOL.39 NO 2/2021 HPT MAGAZINE 35 Events 2021 EVENTS 1–4 HVAC&RFebruaryJAPAN 2022 Tokyo, Japan ACREX17–19index.htmlhttps://www.jraia.or.jp/hvacr/en/FebruaryIndia2022 Bengaluru, India The8–10https://www.acrex.in/homeApril10 th Asian Conference on Refrígeration and Air-Conditioning (ACRA 2022) Chongqing, China 711–13web/index/https://acra2022.scimeeting.cn/en/April th IIR Conference on Sustainability and the Cold Chain Newcastle, United Kingdom 4–6rence-on-sustainability-and-thehttps://ior.org.uk/the-7th-iir-confeMay (postponed from 13-15 September, 2021) IAQ 2020: Indoor Environmental Quality Performance ApproachesTransitioning from IAQ to IEQ Athens, Greece topical-conferences/indoor-environhttps://www.ashrae.org/conferences/CLIMA22–25roachesmental-quality-performance-appMay2022 Rotterdam, The Netherlands 1513–15https://clima2022.org/June th IIR-Gustav Lorentzen Conference on Working Fluids Trondheim, Norway gustavlorentzen_2022/https://www.sintef.no/projectweb/ 131–32021September th IIR Conference on Phase-Change Materials and Slurries for Refrigeration and Air 61–3http://static.gest.unipd.it/PCM2021/ConditioningSeptember th IIR Conference on Thermophysical Properties and Transfer Processes of refrigerants Online event only 523–4http://static.gest.unipd.it/TPTPR2021/September nd AiCARR International Conference Vicenza, Italy and Online 126–8en.aspxhttp://www.aicarr.org/Default_September th International Conference on Compressors and their Systems Online event only 16–18rences/compressorsconferencehttps://www.city.ac.uk/events/confeSeptember (postponed from 13-15 May 2021) 9th IIR Conference on Ammonia and CO2 Refrigeration Technologies Ohrid, Macedonia AHR21–23ration-technologiesference-on-ammonia-and-co2-refrigehttps://iifiir.org/en/events/9th-iir-conSeptemberExpoMexico Monterrey, Mexico 16IIR5–7https://www.ahrexpomexico.com/en/OctoberInternationalConference, th Cryogenics 2021 conference Online event only genics2021www.cryogenics-conference.eu/cryo 14–15 InternationalOctoberSymposium on New Refrigerants and Environmental Technology 2020 Online event only 26–27Kobe2021/en/index.phphttps://jraia-symposium.org/October European Heat Pump Summit Nuremberg, Germany and online Analysis202110–12https://www.hp-summit.de/enNovemberASHRAEBuildingPerformanceConference Denver, Colorado, USA ding-performance-analysis-conferentopical-conferences/2021-ashrae-builhttps://www.ashrae.org/conferences/ ce 16–18 November SIFA Paris, France 16–19https://www.expo-sifa.com/enNovember C&R Madrid, Spain 2022292022https://www.ifema.es/en/crJanuary–2FebruaryASHRAEwinterConference Las Vegas, USA AHR31ces/2022-winter-conference-las-vegashttps://www.ashrae.org/conferenJanuary–2FebruaryExpo Las Vegas, USA https://www.ahrexpo.com/ Please check for updates for any conference that you plan to attend. Venues and dates may change, due to the pandemic. IN THE NEXT ISSUE Climate Leap – how investors reach major emission cuts in existing property portfolios Volume 39 - NO 3/2021

Mission To accelerate the transformation to an efficient, renewable, clean and secure energy sector in our member countries and beyond by performing collabora tive research, demonstration and data collection and enabling innovations and deployment within the area of heat pum ping technologies. Heat Pump Centre A central role within the HPT TCP is played by the Heat Pump Centre (HPC). The HPC contributes to the general aim of the HPT TCP, through information ex change and promotion. In the member countries, activities are coordinated by National Teams. For further information on HPC products and activities, or for ge neral enquiries on heat pumps and the HPT TCP, contact your National Team tact-us/www.heatpumpingtechnologies.org/conat: The Heat Pump Centre is operated by RISE Research Institutes of Sweden. Heat Pump Centre c/o RISE Research Institutes of Sweden P.O. Box 857 SE-501 15 Borås Tel:Sweden+46 10 516 53 hpc@heatpumpcentre.org42 www.heatpumpingtechnologies.org

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Pieve ENEA, Energy Technologies Dept. Tel. +39 050 621 36 maurizio.pieve@enea.it14 JAPAN Mr. Tetsushiro Iwatsubo New Energy and Industrial Technology Development Organization Tel HeatMr.iwatsubotts@nedo.go.jp+81-44-520-5281HideakiMaeyamaPumpandThermal Storage Technology Center of Japan (HPTCJ) Tel: +81 3 5643 maeyama.hideaki@hptcj.or.jp2404 NETHERLANDS Mr. Tomas NetherlandsOlejniczakEnterprise Agency (RVO) Tel: +31 88 60 233 tomas.olejniczak@rvo.nl17 NORWAY Mr. Rolf Iver Mytting Hagemoen Tel.NOVAP+47 971 29 river@novap.no250 SOUTH KOREA Mr. Hyun-choon Cho Tel:KETEP+82 2 3469 energykorea@ketep.re.kr8301 SWEDEN Ms. Emina Pasic Swedish Energy Agency Tel: +46 16 544 emina.pasic@energimyndigheten.se2189 SWITZERLAND Mr. Stephan Renz Beratung Renz Consulting Tel: +41 61 271 76 info@renzconsulting.ch36 UNITED KINGDOM Mr. Oliver DepartmentSuttonforBusiness, Energy & Industrial Strategy Tel: +44 300 068 oliver.sutton@decc.gsi.gov.uk6825 THE UNITED STATES Mr. Van Baxter – Team Leader Building Equipment Research Building Technologies Research & Integration Center Tel: +1 865 574 Ms.baxtervd@ornl.gov2104MelissaVossLapsa – Coordinator Building Envelope & Urban Systems Research Building Technologies Research & Integration Tel:Center+1 865 576 lapsamv@ornl.gov8620 AUSTRIA Dr. Thomas Fleckl Austrian Institute of Technology Tel: +43 thomas.fleckl@ait.ac.at50550-6616 BELGIUM Ellen Van Mello ODE – Organization for Sustainable Energy Tel: + 32 ellen.vanmello@ode.be476792824 CANADA Dr. Sophie Hosatte Ducassy NaturalCanmetENERGYResources Canada Tel: +1 450 652 sophie.hosatte-ducassy@canada.ca5331 CHINA Prof. Xu Wei China Academy of Building Research Tel: +86 10 xuwei19@126.com84270105 DENMARK Mr. Svend Pedersen Danish Technological Institute Tel: +45 72 20 12 svp@teknologisk.dk71 FINLAND Mr. Jussi Hirvonen Finnish Heat Pump Association Tel: +35 8 50 500 jussi.hirvonen@sulpu.fi2751 FRANCE Mr. Paul Kaaijk Tel:ADEME+33 4 93 95 79 paul.kaaijk@ademe.fr14

The International Energy Agency (IEA) was established in 1974 within the fra mework of the Organisation for Economic Co-operation and Development (OECD) to implement an International Energy Programme. A basic aim of the IEA is to foster co-operation among its participa ting countries, to increase energy security through energy conservation, develop ment of alternative energy sources, new energy technology and research and de velopment. Technology Collaboration Programme on Heat Pumping Technologies (HPT TCP) International collaboration for energy efficient heating, refrigeration, and air-conditioning.

Vision Heat pumping technologies play a vital role in achieving the ambitions for a secure, affordable, high-efficiency and low-carbon energy system for heating, cooling and refrigeration across multiple applications and contexts.

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Disclaimer: The HPT TCP is part of a network of autonomous collaborative partnerships focused on a wide range of energy technologies known as Dr. Maurizio