COLD CLIMATE HEAT PUMPS

ARE COMING TO AMERICA

A Sea Change is Now Happening in Heating

In early 2022, the US was still in the grip of a stubbornly persistent pandemic. Supply chain bottlenecks were contributing to creeping inflation and threats of galloping inflation. Hopes of major climate legislation were dashed with the failure to pass the Build Back Better Act [1]. Enthusiasm for heat pumps had waned or was entirely muted at the AHR Expo in Las Vegas in early 2022.

Lukewarm Response in the USA

The contrasts between 2022 AHR Expo in Las Vegas and the 2023 AHR Expo in Atlanta are remarkable, especially with respect to the heat pump technologies. Even so, the installation of heat pumps has not been as strong as climate experts say is needed to meet climate goals. There are several factors behind the lukewarm appeal of heat pumps in the USA.

Firstly, heating has been the domain of fossil fuels for at least a hundred years. Americans replaced their coal- and wood-burning furnaces with gas- and oil-burning furnaces and boilers. Subsequently, ducted central heating, also known as forced-air systems emerged as a uniquely American phenomenon. Such heating systems use ducts, vents, and grilles to distribute heated air throughout a home or building. According to the U.S. Census Bureau, 55 percent of new single-family homes sold in 2022 derived heat from such forced-air systems (compared to 65 percent in 2021) [5].

Ducted central heating systems spurred the adoption of central air conditioning (CAC) in the USA. Typically the same ductwork is used for heating and cooling. In other parts of the globe, hydronic heating using boilers is commonplace and ducted central heating is relatively rare. Although hot water is used for space heating in some regions of the USA, it is much more common in Europe.

Secondly, there is the climate. In climate zones with mild winters, heat pumps have long been used for both heating and cooling; however, until recently, air source heat pumps (ASHPs) have never been seriously considered as a replacement for fossil fuels in the cold climates of midwestern or northeastern states, where much of the population resides. Consequently, the rate of adoption of heat pumps in the USA has been discouraging to global HVACR OEMS (not to mention climate scientists intent on reducing carbon emissions).

Figure 1 – Heat pumps sales surpassed gas furnace sales in 2022 in the U.S. The 2022 figures include sales data for Jan–Nov and projected sales for Dec. (Chart: Canary Media [6].  Source: Air-Conditioning, Heating, and Refrigeration Institute)

A Turning Point

European summers historically have not been extremely hot. Europeans ‎typically have not depended on air conditioning for home comfort. In ‎comparison, the demographics of the USA changed greatly as a result of ‎AC as the quality of life improved in subtropical and tropical regions.

Now, with respect to heating, a turning point may have been reached in the USA. Heat pump sales surpassed gas furnace sales in the USA in 2022, according to AHRI monthly shipment data [6]. (See Fig. 1.) This increase in sales has attracted new players to the market in the USA. Many more companies exhibited heat pumps of one form or another at the AHR Expo in 2023 compared to 2022.

The exhibit space was dominated by global OEM giants such as Daikin, Gree, Haier, Hitachi, LG, Midea, Mitsubishi, Samsung, and others. There were also USA-based OEMs with various models of heat pumps on display. Many of these global giants may just be testing the USA markets to ascertain which products are suitable for North American operations.

It is noteworthy that in 2022 Midea America and Gradient were selected by New York Power Authority (NYPA) to develop new heat pump technology and initially are contracted produce 30,000 new heat pump units for use in New York City Housing Authority residents [7] [8].

Midea is just one among many partners participating in the Cold Climate Heat Pump Challenge working with the U.S. Department of Energy (DOE) to establish consumer incentives to encourage adoption. The Challenge is currently focused on residential, centrally ducted, electric-only heat pumps. There are two segments: one for a CCHP optimized for 5 °F (–15 °C) operation (“5 °F challenge”) and the other for a CCHP optimized for –15 °F (– 26 °C) operation (“– 15 °F challenge”). Detailed challenge specifications are available online [9].

Figure 2 – A single monobloc ASHP can provide domestic hot water as well as hydronic space heating. (Courtesy of Hisense.)

At the 2023 AHR Expo, HiSense (Qingdao, Shandong, China) touted a low energy system for cooling, heating and domestic hot water, delivering outstanding performance even at extreme outdoor temperatures. The company guarantees stable operation even with outdoor temperatures as low as –15 °F (– 26 °C), effectively satisfying the heating demand in extremely cold areas [10].

The HiSense product boasted low-GWP R32 but conventional R410A refrigerants were also common at the AHR Expo. The one major difference between the recent 2023 ISH Expo (Frankfurt, May 2023) and the 2023 AHR Expo was the lack of R290 ASHP products at the AHR Expo compared to ISH Expo. An exception was the PHNIX (Guangzhou, Guangdong, China) Greentherm Air-to-Water HP for space heating and domestic hot water. PHNIX claims stable running at ambient temperature down to –15 °F (– 26 °C) using R290 natural refrigerant [11].

Europe is on a faster track to phase out HFC refrigerants and also to permit the use of R290 in outdoor monobloc evaporators for ASHPs. This was evident in the presence of many units containing R32 as well R290 refrigerant at the ISH Expo.

The evaporators for the ASHPs on display at the AHR Expo typically were comprised of copper tubes with diameters of 9.52 mm (3/8 in.) or 7 mm. Yet there were several companies offering heat exchangers made with 5 mm diameter copper tubes. For example, Amber Enterprises (Haryana, India) [12], Bohn (Querétaro, Mexico) [13], Indus (Sharjah, United Arab Emirates) [14] and Lordan (Kfar Szold, Israel) [15] were promoting the manufacture of coils based on 5 mm or 7 mm diameter copper tubes [12-15].

Heat pump designs on display at the AHR Expo to some degree reflect the existing housing stock and the climate zones. As an economical alternative to ground source heat pumps (GSHP), different types and sizes of air source heat pumps (ASHPs) accounted for the wide array of products on display. Types of ASHPs include Air-to-Air (ATA) and Air-to-Water (ATW) heat pumps. Another distinction is made between split system heat pumps and (outdoor) monobloc heat pumps.

Also, midsize systems for multifamily homes and light commercial buildings were prevalent, for example, 20 refrigeration ton (RT) systems (equivalent to 240,000 BTU/h, or 70 kW). These systems can provide space heating and domestic hot water in apartment complexes. They lend themselves well to variable refrigerant flow (VRF) and the use of large outdoor evaporators. Indeed, they may be the low-hanging fruit in the push toward decarbonization.

Especially for retrofits, where the heat pump replaces a central furnace, a closed loop system (secondary loop) may be installed between the heat pump and the ductwork. A closed loop is a circulation loop where a particular medium (water, glycol, etc.) is continuously circulated around a system of piping.

In this case, the fluid passes inside the tubes of an air handler and forced air picks up the heat and distributes it through the home. This cascaded system combines an ATW heat pump with an air handler and the net effect is the same as an ATA heat pump.

An ATW heat pump is suitable for replacing the boiler in hydronic heating systems, which distribute hot water through pipes. Hydronic space heating is accomplished through conventional radiators, in-floor radiant heating or floorboard heaters. In the case of an ATW heat pump, the condenser may take the form of a brazed plate heat exchanger, which transfers heat from the hot compressed refrigerant to the water for use in space heating or domestic hot water.

For ASHPs with a secondary loop, the refrigerant path is restricted to the outdoors. These self-contained units are commonly referred to as monoblock heat pumps, or “monoblocs.” (See Figs. 2 and 3.)

Monobloc ASHPs can be used for space heating or domestic hot water (DHW) or both. These have different temperature requirements, and their efficiency depends on the outdoor temperature. Heat pumps that are specifically designed to be effective in cold climates are generally referred to as Cold Climate Heat Pumps (CCHPs).

Monobloc ASPHs with small-diameter copper tube heat exchangers have the potential to reduce refrigerant charge and enable the use of natural refrigerants such as R290, which have an ultralow GWP and do not pollute the environment.

Figure 3 – An outdoor ATW HP can be coupled with a multi-function tank to provide domestic hot water and space heating as well as space cooling and tap water. (Courtesy of PHNIX.)

Cold Climate Heat Pumps

Cold climate heat pumps (CCHPs) could be a game changer in the adoption of heat pumps. CCHPs raise the possibility of drastically reducing the energy requirements for heating in large swathes of the Northeast and Midwest. They deliver high COPs for most heating days when temperatures are near freezing.

In other words, they are energy amplifiers even at freezing temperatures. This is seen on a phase diagram where the work done by the compressor is multiplied by the heat absorbed by the refrigerant at the outdoor evaporator. 

One way to make CCHPs even more efficient in gathering heat from a cold outdoor ambient is to use smaller diameter copper tubes. This has been demonstrated in many, many designs, As few as ten years ago, heat pumps were made with 7 mm diameter copper tubes. However, as coil makers mastered the production of heat exchangers with even smaller diameters tubes, it was realized that such coils extend the range of operation of such heat pumps (Fig. 4).

Figure 4 – Smaller diameter copper tubes (5 mm or 7 mm) are in demand as OEMs discover their advantages in a variety of applications including evaporators for monobloc CCHPs. (Photograph Courtesy of Lordan.)

Conclusion

Heat exchanger engineers and policy makers from around the world met at the triannual IEA Heat Pump Conference in Chicago, and they will also meet at the quadrennial IIR International Congress of Refrigeration in August. It can be expected that the pace of product innovation, ramping up of production and market expansion will only increase in the coming years and the best designs will win over the market!

Right now, it is still too early to pick the winning technologies and companies but it should be noted that ATW HPs have many benefits for space and water heating. The industry is bracing for a period of rapid transition, comparable to the transition to propane in the refrigeration industry and the perfection of R744 supermarket refrigeration systems.

Much of this change will be driven by the existence of a robust supply chain, one that can meet the demand for smaller diameter copper tubes as well as the heat exchangers made from these tubes.

On thing is certain. Cold climate heat pumps are coming to America … perhaps sooner than anticipated.

References (Main Article)

1. The White House, “The Build Back Better Framework,” https://www.whitehouse.gov/build-back-better/
2. The REPowerEU plan, May 2022 https://commission.europa.eu/publications/key-documents-repowereu_en.
3. MicroGroove Update, “Heat Pumps Gain Popularity in China” (Vol. 12, Number 1) and “Europe Turns up the Heat on Heat Pumps” (Vol. 12, Number 2.)
4. The White House, Inflation Reduction Act (IRA) Guidebook. https://www.whitehouse.gov/cleanenergy/inflation-reduction-act-guidebook/
5. U.S. Census Bureau, New Single-family Homes in 2022, Infographic. https://www.census.gov/construction/chars/interactive/index.html
6. Maria Virginia Olano,“Chart: Americans bought more heat pumps than gas furnaces last year,” Canary Media. 10 February 2023. Monthly Shipments | AHRI (ahrinet.org). https://www.canarymedia.com/articles/heat-pumps/chart-americans-bought-more-heat-pumps-than-gas-furnaces-last-year
7. Governor Hochul and Mayor Adams Announce $70 Million Initial Investment to Decarbonize NYCHA Buildings as Part of Clean Heat for All Challenge https://www.governor.ny.gov/news/governor-hochul-and-mayor-adams-announce-70-million-initial-investment-decarbonize-nycha
8. The Gradient Team, “It's getting hot in here: How we build your Gradient's mighty heat pump, June 10, 2022. https://www.gradientcomfort.com/blogs/behind-the-scenes/how-to-build-a-planet-friendly-air-conditioner
9. U.S. Department of Energy, “Residential Cold-Climate Heat Pump Technology Challenge Specification and Supporting Documents, Version 1.2,” September 24, 2021. https://www.energy.gov/eere/buildings/cchp-technology-challenge-specifications. See also: https://www.energy.gov/eere/buildings/partners
10. HiSense Hi-Therma R32 Monobloc. https://www.hisensehvac.com/atw/index.aspx?nodeid=7 See also “Hisense HVAC Global: Reimagine your solution” https://www.hisensehvac.com/hvac/index.aspx?nodeid=4
11. PHNIX, 2023-24 Catalog Eco-Friendly Heat Pumps. https://www.phnix-e.com/detail/2525.html
12. Amber, “Components ( RAC & Non-RAC)” https://www.ambergroupindia.com/components-rac-non-rac/
13. “Leader in Manufacturing of Condensing Units and Evaporators and Racks for Refrigeration,” https://bohn.com.mx/
14. Indus Engineering, "Heat Exchanger Design Case Study Monobloc Heat Pump Evaporator” https://indusair.com/templates/indusair_default/images/monobloc_heat_pump_evaporator.pdf. See also: https://indusair.com/products/copper-heat-exchangers
15. Lordan https://www.lordan-coils.com/ https://www.lordan-coils.com/?section=25

IN THE SPOTLIGHT

Triennial Heat Pump Conference Returns to North America with Big Ideas

New Research Advances the “Decade of the Heat Pump"

The Paris Agreement aims to achieve net zero carbon by 2050. The march toward net zero is measured in decades yet every year counts. The next ten years will be especially crucial for addressing climate change.

A key player in the march toward net zero carbon is the International Energy Agency (IEA) along with the Heat Pumping Technologies (HPT) Technology Collaboration Programme (TCP).

The mission of the IEA HPT TCP is “to accelerate the transformation to an efficient, renewable, clean and secure energy sector in its member countries and beyond through collaboration research, demonstration and data collection and through enabling innovations and deployment in the area of heat pumping technologies.”

One specific objective is to hold an international conference at least once every three years. Recent conferences have been held in the following cities in the past decade.

• Chicago, Illinois (2023)
• Jeju Island, South Korea (2020 postponed to 2021 hybrid event)
• Rotterdam, Amsterdam (2017)
• Montreal, Canada (2014)

Following this schedule of alternating continents, the HPC won’t be back in North America until at least 2032. Meanwhile, the US set a goal for 2030 of reducing GHG emissions by 50 to 52 percent below 2005 levels [1]. Meeting this 2030 goal is crucial to decarbonizing the power sector by 2035 and achieving a net zero carbon by 2050.

The 2020s has already been described as the “Decade of the Heat Pump,” according to Tom Nowak of the European Heat Pump Association (EHPA) [2].

The Chicago HPC conference delivered this message loud and clear. It covered a wide range of topics, including (a) market trends, (b) refrigerants and (c) technologies and systems. This “Spotlight” reviews a small subset of the scores of papers shared at this pivotal conference.

Market Trends: USA and Europe

There has been steady growth in the heat pump market in the USA in the past decade as outlined by Malhotra et al. in the paper “Heat Pumps in the United States: Market Potential, Challenges and Opportunities” [3].

Simultaneously, great strides have been taken in Europe [4]. One of the highlights of the IEA HPC was a presentation by Thomas Nowak from the European Heat Pump Association. According to the EHPA, heat pump sales were up by 38 percent in 2022, with 3.0 million units sold across 21 countries representing the EHPA, increasing the current European heat pump stock from 17 million to 20 million units (Fig. 1). That is almost hockey stick growth, which is quite encouraging. Nowak provides a detailed country by country review of heat pump trends and policies in Europe. He concludes his paper with the following comments:

“The European heat pump industry has reached a level of maturity perfectly suited for exponential growth throughout this decade.”

[…]

“Accelerating its growth even further and stabilizing sales needs strong and visible support by governments, including establishing a European heat pump strategy that addresses and supports all parts of the value chain and coordinates the ambition of member states.

[…]

“If this is established, heat pumps can become the #1 heating and cooling technology in Europe, meaningfully contributing to the continent’s energy and climate targets and removing its dependence on Russian gas, making renewable heat available and affordable for all for the next winter and the winters to come.”

A similar sentiment is described in a detailed review of heat pump markets in the United States by Malhotra et al. which is available for free download from the HPT website [3].

Figure 1 – Three million units were sold across the 21 countries representing the EHPA, increasing the current European heat pump stock from 17 million to 20 million units [4].

Refrigerants: Opportunity or Stumbling Block?

With respect to F-gas phasedown and decarbonization, long term policies need to be clarified to secure the investments that are needed to accelerate the transition to a clean energy future.

Low-GWP A2L refrigerants were the focus of much recent research as presented in Chicago. Researchers from Trane, ORNL, Daikin, University of Illinois Urbana and other laboratories presented papers on the properties of HFO blends that are candidates for low-GWP refrigerants [5-11].

For example, Li et al. from ORNL presented a paper titled “Optimization of a Residential Air Source Heat Pump using Refrigerants with GWP <150 for Improved Performance and Reduced Emission” [5].

One purpose of Li and his colleagues was to optimize the designs of multiple-row 5 mm, 7 mm, and 9 mm tube coils with low-GWP refrigerants and compressors to determine the performance improvements. For the same coil width and coil height as the baseline coils, the 5 mm tube heat exchangers had six more tubes in each row and more tube rows due to smaller horizontal and vertical tube spacing. They concluded that “the optimal systems using R454C, R455A and R457A with 5 mm tube heat exchangers outperform the baseline R410A heat pump product.”

Technology Trends in Germany

Visualization of Solutions at Fraunhofer

Marek Miara from the Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany, developed a system of classification of heat pump solutions for multifamily buildings [12]. Heat pump products and building solutions are classified according to a simplified schematic for the visualization of multifamily buildings. This project was developed within the context of Annex 50 and will continue as part of Annex 62 on “Heat pumps for multifamily buildings in cities.”

RWTH LCA Study

A Life Cycle Analysis (LCA) of heat pumps can guide policies for reducing energy consumption and greenhouse gas (GHG) emissions. According to Vering et al. [13], 19 million residential buildings in Germany consume about 865 TWh of fossil fuels and emit about 120 million tons of CO₂ each year, mainly for heating purposes. The authors hail from RWTH Aachen University (or Rheinisch-Westfälische Technische Hochschule Aachen), a public research university in North Rhine-Westphalia.

RWTH is the largest technical university in Germany. We can refer to the paper by Vering et al. as “the RWTH LCA study.”

The RWTH LCA study assumes a linear progression between the German electricity (GE) mix from 2018 and the European electricity mix from the Sustainable Development Scenario (SDS) of the International Energy Agency (IEA) for 2040. For a seasonal COP (SCOP) of 3.1 and a predicted increase in the share of renewable energies in the German electricity mix, a heat pump decreases greenhouse gas emissions over the entire life cycle by 54 percent compared to a gas-fired condensing boiler. (The name "condensing boiler" derives from the energy recovered though the condensation of water vapor from the exhaust gas.)

Energy efficiency may be the most important but it’s not the only environmental impact of replacing gas-fired condensing boilers with heat pumps. Sixteen different environmental categories were examined with respect to seven different refrigerants, including R410A, R32, R1234yf, R290, R1270, R600a and R717.

The type of refrigerant had an effect on several of the environmental categories. For example, the use of R717 (ammonia) refrigerant is incompatible with copper, so its use affects the environmental category of “material production.” The LCA database “ecoinvent” was used by the RTWH team to obtain the environmental impacts of material and energy used for the production of refrigerants as well as the construction and operation of heat pumps [14].

Based on the 16 environmental categories, the RWTH LCA study addresses the concept of “burden shifting,” including cases where a heat pump causes higher environmental impacts than a gas-fired condensing boiler.

With respect to refrigerants, the authors recommend the use of R290 in residential heat pumps based on its high achievable efficiency. Also, R290 is non-toxic; it has a low GWP; and it is already used in heat pumps for residential buildings. The disadvantages of R290 are its high flammability and classification in safety class A3. In addition, DIN EN 378 restricts possible installation sites for R290 heat pumps.

China Goes Large

Gigantic Project in Zhao County, Hebei Province, China

China officially became an affiliate of the IEA in 2015. It currently is an “association country” rather than a “member country.”

China is endeavoring to match products with multifamily buildings as evidenced by a paper by Zhao et al. on the “Largest Air Source Heat Pumps Central Heating Project in China” [15].

Participants included Guangdong New Energy Technology Development Co., the China Heat Pump Alliance (CHPA), Emerson Climate Technologies (Suzhou) Co., and the Harbin Institute of Technology. Emerson Climate Technologies is now "Copeland," having been renamed after the Blackstone Group acquired a majority stake in the company [16].

Zhao et al. describe one of the biggest ongoing ASHP heating projects in the world. More than 1,200 units of ASHPs were deployed as heating sources for approximately four million square meters of living spaces in large residential buildings. (Note that 4,000,000 sqm is about 43,000,000 sqf.)

That’s enough heating for a community of about 30,000 apartments in a cold region of China. Zhao County is in the southwest of Hebei province. It is about 280 km (170 mi) south of Beijing. In 2019, the local government decided to replace coal-burning power plants with ASHPs to reduce running costs and air pollution. This part of north China has cold winters and space heating in winter. The heat source from two coal-burning power plants caused serious air pollution.

Figure 2 – More than 1,200 units of ASHPs were deployed as heating sources for large residential buildings in Zhao County.

The space heating necessary during the heating season was calculated as 138 MW. Previously two coal burning plants were necessary to produce this amount of heating. Instead 1200 ASHP units producing 120 kW of heating each could potentially produce 144 MW of heating. The challenge was how to best distribute these units and move the heat from the ASHPs to the living spaces.

The heating medium was low temperature water. The water was supplied at 55 °C (131 °F) and returned at 45 °C (113 °F) at the end of radiator. For floor heating, the water was supplied at 45 °C (113 °F) and returned at 35 °C (95 °F) at the end of floor heating.

For this large and complex project, detailed knowledge of the climate was essential to determine the initial investment and operating costs. From the beginning, the historical climate and environmental characteristics of Zhao County were investigated.

Figure 3 – To avoid the cold island effect, frame structures keep the outdoor units at least 8 meters above the ground.

Another key factor was to avoid the “cold Island” effect, which occurs if the air circulation around the ASHP units is not optimized. In this case, the stations were designed as frame structures at least 8 meters above the ground. That allows cold air from the units to flow downward into nearby open spaces. The ASHP units at each station are arranged inline with no more than 3 units in the row direction.

Some other features of the ASHP were the use of vapor injection technology for the compressors of ASHP unit. The winter climate record data indicated that ambient temperature could go as low as – 15 °C. Vapor injection technology brings the benefits for ASHP heating in cold ambient conditions. According to Copeland laboratory test results, this technology can improve heating capacity by 21 to 40 percent and efficiency by 7 to 22 percent, depending on the ambient temperature.

Vapor injection technology allows the system to be used down to ambient temperatures as low as – 30 °C, delivering hot water at temperatures high enough even for radiators.

The 1,200 units of ASHP were managed with higher system performance in mind, using Internet of Things (IoT) technology. Depending on the temperatures of outlet water and return water, the operation of the individual ASHPs could be adjusted for better system efficiency.

This project serves as a real world example from which much can be learned about large scale implementation of heat pumps in cold regions.

It’s worth a close look.

Table 1 – Benefits of Vapor Injection Technology

Cold Climate Heat Pumps in Canada

A data-rich examination of residential heat pumps in Canada by the Natural Resources Canada’s CanmetENERGY in Varennes (outside of Montreal) was provided in a session keynote by Tamasauskas et al. [17]. Considering Canada’s cold climates, it was a subject of great interest with respect to the decade of heat pumps!

The authors used data driven simulations to develop a comprehensive

overview of the technical and economic potential of heat pumps as replacements for natural gas furnaces, oil furnaces, and electric baseboard heating in Canadian residential buildings in four regions, including Halifax, Toronto, Winnipeg, and Vancouver.

According to the authors, Conventional Variable Capacity Air-Source Heat Pump (VCHP) are a popular option in Canada, because they are able to efficiently modulate their capacity to better match heating or cooling demand. However, these systems are not necessarily well adapted to cold climates.

Instead Cold Climate Variable Capacity Heat Pumps (CCHP) are a better choice. CCHPs combine variable speed compressor technologies with other upgrades such as larger outdoor heat exchangers and vapor injection

cycles. CCHPs maintain a higher portion of heating capacity at low outdoor temperatures. The authors classify cold climates as systems operating down to outdoor temperature of – 25 °C (– 13 °F) while maintaining at least 65 percent of their rated heating capacity.

Analysis using planned carbon pricing shows that by 2030 heat pumps will offer both utility and lifecycle cost savings compared to natural gas furnaces, oil furnaces or electric baseboards. Yet the higher first cost of heat pumps remains a challenge. The authors suggest that these results can be used as a starting point to support the future policy and incentive programs needed to drive the decarbonization of Canadian residential buildings

The research center in Varennes employs more than 150 scientists, engineers, technologists, managers and support staff [18].

USA on the Move

As mentioned in the main article of this issue, there is also movement in the USA heat pump marketplace. Currently air-to-air (ATA) reversible air-conditioners are counted as “heat pumps” in USA but not in European statistics. The reasons for this discrepancy may be that air conditioning is not as common in Europe as in the USA. By way of comparison, there are many similarities between the USA and China as described in a previous issue of the MicroGroove Update newsletter [19].

The USA market could become one of the largest and most lucrative markets for heat pumps in the next decade.

Perils of Boom or Bust

Many papers were dedicated to strategies for cracking the heat pump market in the USA. What will be the role of government, tax rebates and incentives? Frank and Kinsey from “Sealed” (based in NYC) examined the pitfalls of boom-and-bust incentive programs [20]. In other words, consistent incentive programs are recommended to provide stability in the marketplace.

Data Is King at TECH Clean

Kameia and Kischa provided a detailed overview of the TECH Clean California initiative [21]. TECH Clean California is a $120 million, multiyear market

transformation initiative. It is focused on accelerating adoption of heat pump technology through the following tactics:

• driving down costs
•  finding new value streams
•  scaling successful approaches through market and policy changes

The goal is six million installed heat pumps by 2030 and carbon neutrality by 2045. An important component of the initiative is data collection and data transparency. In other words, bolster what works and exit what doesn’t work.

The TECH Clean initiative has three pillars of incentives, pilot programs, and public reporting. The vision for public reporting is “to bring a variety of data sources together and layer them into a robust and scalable data pipeline that offers novel visibility into the California heat pump market.”

In this manner, every project and program is tracked and its statistics of success or failure steer future directions. California has long been a bellwether for environmental policy so this data pipeline is worth monitoring to understand what works … and what doesn’t work.

Multifunction Heat Pump

One particularly troublesome aspect of California’s environmental policy is the stubbornly slow rate of adoption of heat pumps for domestic hot water (DHW). Natural gas continues to dominate as the preferred energy source for DHW It has been a challenge to change this market in California and across the United States.

Chakraborty and Levering from the Western Cooling Efficiency Center (Davis, California) and Chally from Frontier Energy (Davis, California) explored the possibility of cracking this market through the development of a Multi-Function Heat Pump (MFHP) using off the shelf components. This compelling idea is explored in the “Enabling Electrification of Domestic Hot Water and Space Conditioning with Multi-function Heat Pumps” [22].

MFHP system moves heat from space into the DHW tank while operating in a simultaneous space cooling and hot water heating mode. The simultaneous mode performed 36 percent better than individual two modes if operated separately. The next steps are refrigerant charge optimization and advanced controls to increase the run-time of the simultaneous AC and DHW modes.

Conclusion

The Heat Pump Conference convened in the USA at a pivotal point in history as countries around the globe are intent on transitioning to clean heating to realize commitments to net zero carbon.

The HPC provides a unique venue for stakeholders to share their successes and plan for the future. There is growing recognition that the use of heat pumps for DHW and space heating offers a gigantic opportunity to reduce dependency on fossil fuels.

The HPC is only one activity within the HPT TCP. If you have anything to do with the Research, Development, Demonstration, and Deployment (RDD&D) of heat pumping technologies then HPT TCP can be an important ally.

(See "What is the IEA HPT TCP?" below for more about the framework of this Technical Collaboration Programme.

References (In the Spotlight)

Papers from the proceedings (2023 HPC Proceedings) are currently available to attendees with a passcode and will be made available for free downloading here:

https://heatpumpingtechnologies.org/publications

1. Aliyah Kovner. “A 50% Reduction in Emissions by 2030 Can be Achieved. Here’s How,” News from Berkeley Lab, June 2, 2022 https://newscenter.lbl.gov/2022/06/02/emissions-reduction-roadmap/

2. Thomas Nowak, “Making progress in the decade of heat pumps – status and trends of

the European heat pump markets in 2022,” 14th IEA Heat Pump Conference (2023 HPC Proceedings) Paper 959

https://www.hpc2023.org/proceedings/

3. Mini Malhotra, Zhenning Li, Xiaobing Liu, Melissa Lapsa, Tony Bouza, Edward Vineyard, Brian Fricke, “Heat Pumps in the United States: Market Potentials, Challenges and Opportunities,” HPT Magazine, Vol. 41 No. 1 (2023) p. 27. https://heatpumpingtechnologies.org/publications/heat-pumps-in-the-united-states-market-potentials-challenges-and-opportunities/

4. IEA Heat Pump Technologies, Field News, “Growth record for European Heat Pump Market - 2022 Best Year so Far,” 21 Feb 2023. https://heatpumpingtechnologies.org/news/1/58309.

5. Zhenning Li, Samuel F. Yana Motta, Bo Shen, Hanlong Wan, “Optimization of a Residential Air Source Heat Pump using Refrigerants with GWP <150 for Improved Performance and Reduced Emission,” 2023 HPC Proceedings, Paper 1974.

6. Michael Petersen, Steve Kujak, Gurudath Nayak, “ Evaluation of lower GWP alternatives to R410A in AC and HP applications,” 2023 HPC Proceedings, Paper 123.

7. Sarah Kim et al., “Testing of alternative refrigerants for unitary air-conditioning and heat pump applications,” 2023 HPC Proceedings, Paper 127.

8. Ivan Rydkin, Tsubasa Nakaue, Alvaro Leon, “Novel HFO Refrigerant Blend R-474A for GWP <1 Automotive Heatpump Application,” 2023 HPC Proceedings, Paper 266. 

9. Hieu et al., “Flow Boiling Heat Transfer Performance of R448A inside Multiports Mini-Channel tubes with ‎different geometry,” 2023 HPC Proceedings, Paper 376,

10. Sugun Tej Inampudi and Stefan Elbel, “Experimental Investigation Into the Effect of Charge Optimization And Standard Test Conditions On ‎The Seasonal Performance In An R410A Heat Pump With Dedicated Subcooler,” 2023 HPC Proceedings, Paper 506.

11. Mohammed et al., “Searching for eco-friendly working fluids for an ejector-driven heat pump for domestic water heating,” 2023 HPC Proceedings, Paper 939.

12. Marek Miara, “General classification of heat pumps solutions for multi-family buildings,” 2023 HPC Proceedings, Paper 878.

13. Vering et al., “Towards integral assessment of heat pumps and refrigerants using LCA: A case study for the German ‎building stock,” 2023 HPC Proceedings, Paper 311.

14. G. Wernet et al. “The ecoinvent database version 3 (part I): overview and methodology,” Int. Journal of Life Cycle Assessment, vol. 21, no. 9, pp. 1218–1230, 2016, doi: 10.1007/s11367-016-1087-8.

15. Zhao Mishen, Wang Huping, Zhao Hengyi, Xie Sherry, , Ni Long, “Case Study of the Largest Air Source Heat Pumps Central Heating Project in China,” 2023 HPC Proceedings, Paper 110.

16. “Blackstone Completes Acquisition of Copeland, Formerly Emerson Climate Technologies,” ABF Journal.

June 1, 2023. https://www.abfjournal.com/dailynews/blackstone-and-emerson-complete-acquisition-of-copeland-formerly-emerson-climate-technologies

17. Justin Tamasauskas, Laurence Rousseaua, Alex Lachancea, Martin Kegela, “Assessing the potential of air-source heat pumps in the Canadian residential sector,” 2023 HPC Proceedings, Paper 514.

18. https://natural-resources.canada.ca/energy/energy-offices-and-labs/canmetenergy/canmetenergy-varennes/5761

19. “Heat Pumps Gain Popularity in China,” MicroGroove Update, vol. 12, no. 1. https://microgroove.net/microgroove-update-newsletter

20. Andy Frank Nate Kinsey “The Performance Playbook: A policy strategy for scaling heat pump adoption with happy consumers and utilities,” 2023 HPC Proceedings, Paper 1127. See also “Sealed Resource Library,” https://sealed.com/resource-library/

21. Evan Kameia, Teddy Kisch, “TECH Clean California: Paving the Way to Heat Pump Market Transformation,” HPC Proceedings, Paper 329.

22. Subhrajit Chakraborty, Stephen Chally, Timothy Levering, “Enabling Electrification of Domestic Hot Water and Space Conditioning with Multi-‎‎function Heat Pumps,” HPC Proceedings, Paper 192.

Sidebar: What is the IEA HPT TCP?

IEA member countries and association countries now represent over 80% of global energy consumption (up from 40% in 2015). IEA data and reports are well known in the energy world. The Agency collects and distributes authoritative energy data from more than 180 countries through its Energy Data Centre. https://www.iea.org/data-and-statistics

The IEA was created in response to the 1973-1974 oil crisis. Since then the IEA has modernized its strategy to provide a greater focus on clean energy technology, including energy efficiency. IEA members agreed in March 2022 to guide countries as they build net-zero emission energy systems to comply with internationally agreed climate goals, and to broaden the Agency’s scope to include the critical minerals and metals needed to develop clean energy technologies.

What is a TCP?

The IEA organizes a vast Technology Collaboration Programme, which consists of scores of specialized TCPs, including five TCPs relating to buildings. https://www.iea.org/about/technology-collaboration/buildings. One of these is the Heat Pumping Technologies (HPT) TCP. https://heatpumpingtechnologies.org/ongoing-annexes/

What is an Annex?

Projects within the HPT TCP are known as “Annexes.” Annexes typically run for three years. They include several countries with one country typically designated as the “Operating Agent,” that is, the project leader. There are currently nine annexes active within the HPT TCP. New annexes are added as old annexes complete their tasks. A list of current Annexes can be found of the website for the HPT TCP https://heatpumpingtechnologies.org/ongoing-annexes/

As an example, Annex 54 on “Heat Pump Systems with Low GWP Refrigerants” expires this year. An annual report is available online. Annex 64 on “Safety Measures for Flammable Refrigerants” is the new initiative created to address industry needs for low GWP refrigerants. https://heatpumpingtechnologies.org/annex64/

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White Papers Recently Published in Appliance & HVAC Report

www.appliancehvacreport.com

Frank Gao, Kerry Song, Yoram Shabtay, and Harry Schmitz, Appliance & HVAC Report, “Heat Pumps ‎Deliver High Efficiency Heating: Five Trends in Heat Pump Design for Residential Heating,” October ‎‎2022, Page 10.‎

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2022 ATMOsphere America Conference (slideshow):

A Cold Climate R290 Heat Pump Water Heater Case Study, Yoram Shabtay, Heat Transfer Technologies and Peter Mostovoy, Lordan Coils

Heat Pump Session, 7 June 2022

Upcoming Events

26th IIR International Congress of Refrigeration, Paris, France, 21-25 August 2023

European Heat Pump Summit, Nuremberg, Germany, 24-25 October 2023