Industry Commitment: Trane Homes is pleased to join the CCHP Challenge, noting that it is fulfilling the industry’s commitment to reduce carbon emissions by building sustainable heat pumps. (courtesy of Trane)
The United States and most other developed countries are developing and implementing decarbonization policies to move away from the use of fossil fuels for space heating. The reason for this shift is to reduce carbon emissions from heating appliances and the resulting combustion-related air pollution.
To amplify this shift, many US cities have proposed or passed ordinances to ban fossil fuels from new homes and buildings. In most cases, this will result in the installation of all electric heat pumps (HPs) rather than gas heating in new construction projects. The problem is that while modern HPs perform well in temperate climates such as the Pacific Northwest and much of California, they tend to suffer performance degradation in colder regions such as the Northeast and upper Midwest. .
Thus, the problem of cold climate heat pumps (CCHP) needs to be addressed, which the Department of Energy (DOE) hopes will lead to the development of new heat pump technologies that will improve performance at low temperatures, increase heating capacity at lower temperatures. ambient temperature Provides higher efficiency in field conditions. Six OEMs have risen to the challenge and are now working with the Department of Energy and other stakeholders to create the next generation of heat pumps that can be used in any climate.
The CCHP challenge is currently focused on residential, central plumbing, pure electric HP and consists of two parts: CCHP optimized for 5°F (-15°C) operation and CCHP optimized for -15° operation F (-26°C). . The performance specifications will surpass existing products on the market today to meet the 2024 commercialization deadline (see Table 1 below). The challenge also requires the use of low-GWP refrigerants, grid interoperability, and the inclusion of an electrical thermal stage.
OEMs such as Trane Residential are excited to join the challenge, noting that it is fulfilling the industry’s commitment to reducing carbon emissions by promoting sustainable HP technologies that use fossil fuel-based equipment to meet homeowners’ heating needs .
“This challenge supports our shared goal of drastically reducing energy demand and carbon emissions, while at the same time innovating with an eye towards a better world.” “We boldly challenge the possibility of sustainable peace.”
Johnson Controls agrees that this challenge represents a significant opportunity to scale up the adoption of heat pumps, which can replace and eventually replace combustion and resistive heat sources. “CCHP technology is helping to accelerate innovation in this area and brings us one step closer to achieving a zero-carbon economy,” said Mark Lessans, Director of Regulatory and Environmental Affairs, Johnson Controls.
While CCHP is recognized in some regions with the support of government, industry, and utility initiatives, the Department of Energy’s challenge will help eliminate common technical and market barriers to promote wider adoption among consumers, including 5°F performance at temperatures up to and below, installation issues and networks. impact during periods of peak demand, said Lennox Industries senior product marketing manager Brandon Chase.
CCHP Roundtable: US Department of Energy Secretary Jennifer Granholm and Massachusetts Secretary of Energy and Environmental Protection Kathleen Theocharides listen to a presentation on cold climate heat pumps at a roundtable in Boston. (Courtesy of Mitsubishi)
“Lennox is excited to be part of the CCHP Technology Challenge,” he said. “By entering the competition, Lennox is supporting its commitment to reduce greenhouse gas emissions and fight climate change by helping to develop, commercialize and deploy next-generation CHP plants that meet consumer needs for comfort and efficiency in North American cold climates.”
This task is necessary because the new regulations will force Americans to replace their fuel-fired stoves and heating systems with HP all-electric ones. Mark Kunz, CEO of Mitsubishi Electric Trane HVAC US (METUS), said the new CCHP technology will allow them to enjoy increased comfort as well as greater efficiency and sustainability.
“High-efficiency, variable-displacement heat pumps, in particular, can provide the superior personal comfort our society needs to galvanize public support for decarbonization and mitigate practical issues such as grid impacts during peak periods,” he said. Given the urgency of energy transition and decarbonization, the U.S. Department of Energy recognizes the need for next-generation manufacturers to support innovation and remove market barriers to encourage greater consumer adoption of heat pumps. New heat pumps will operate at a lower cost than existing models temperatures while maintaining high efficiency.
Ideally, this challenge should address multiple challenges, said Todd Nolte, Carrier’s senior director of strategy and regulation for residential HVAC products. First, a test program will be developed in collaboration with the Department of Energy and participating OEMs to verify the performance of the CCHP through laboratory testing.
“Second, this challenge will help accelerate the development of the next generation of heat pumps to meet consumer needs for comfort and efficiency in extreme cold climates,” he said. “Using electricity as the sole fuel source for heat pumps creates significant opportunities to reduce carbon emissions compared to traditional gas-fired heaters. Third, through collaboration with utilities and government partners, this will lead to the creation of incentive programs to promote market acceptance. If these goals are achieved, the long-term market potential is huge.”
Creating new CCHP technology can be difficult as the US Department of Energy target requires heat pumps to achieve 2.4 COP and 100% heat output at 5°F. According to Lessans, the Northeast Energy Efficiency Partnership (NEEP) currently uses a CCHP specification of 1.75 COP at 5°F, which is a significant improvement in efficiency at low ambient temperatures.
“When redesigning the CHP plant for the needs of the Department of Energy, the focus will be on optimizing the compressor heating system so that the new system can maintain efficiency and performance requirements at 5°F,” he said.
Ductwork: The CCHP challenge only includes ducted heat pumps because most US homes have a central HVAC system with ductwork that provides conditioned air throughout the home. (provided by the carrier)
There are several approaches that can be taken to improve the performance of a heat pump in cold climates. These include, but are not limited to, cascaded cooling systems, various forms of multi-stage compression, vapor injection and liquid injection, said Jason Leroy, Trane Technologies director of advanced technology, residential HVAC and supplies.
“The optimal solution will take into account the trade-off between customer needs, product cost, operational efficiency, reliability and technology readiness,” he said. “It’s all about maximizing value for our customers while meeting their comfort needs.”
The next-generation METUS CCHP will include advanced reflow and reheat inverter technology to deliver efficient high-volume heating at lower temperatures than current models, Kunz said. Their heat pumps will also include control and connectivity features to mitigate peak demand issues and expand the use of renewable energy. Faced with the challenge, CCHP may need to use flammable (A2L) refrigerants with a GWP below 750.
“Low-GWP refrigerants under consideration have better efficiency and performance than R-410A, but may require safety features such as leak detection, shut-off valves and additional ventilation,” said Eric Dubin, Senior Director, Utilities and Performance Improvement. in METUS “A2L refrigerants are more flammable than R-410A but less likely to ignite or sustain a flame than hydrocarbons. sustainable built environment.
Although the goal of the US Department of Energy was to create an efficient heat pump that would provide enough heat in very cold climates, most CHP applications still require some form of back-up heating.
“This is because the rated heating capacity of a heat pump is relatively small compared to a furnace, and the heating capacity is inevitably reduced at ambient temperatures below 5°F,” Lessans said. “The DOE task was for the project participants to use conventional electrical resistance technology to provide backup heat. However, in addition to resistive heating, CHP can also be integrated with backup furnaces that only operate when the heat demand exceeds CHP capacity. Combined system This improves demand response outcomes by reducing emissions at source, reducing utility bills and reducing electricity consumption, which is critical to grid sustainability.”
DOE specifications call for staggered auxiliary heating (see Table 2 below) and the new CCHP will provide significant heating capability down to -15°F. This is why METUS expects backup heating to only run for a few hours a year, if at all.
“Typically, auxiliary heating is rarely activated in homes using our current superheat units, which provide heating capability down to -13°F,” Dubin said. “The new HP system will include controls for a coordinated conversion. Resistance heating is a viable backup heating option, especially in new buildings, while retrofits can use an existing furnace or boiler as a secondary system.”
Davis noted that OEMs won’t have much time to work on their CCHPs as the DOE Challenge program requires proven lab prototypes to be built in early to mid 2022. Field trials of prototypes will begin in the winter of 2022-2023 and will likely continue in the winter of 2023-2024, with the final product on the market in 2024. “Our plan is to deliver CCHP within the time frame set by the Department of Energy’s task,” she said.
Other OEMs believe they, too, will have products ready on time, and are taking advantage of this unique collaboration opportunity to drive significant advances in HP technologies. Chase said Lennox looks forward to working with other industry leaders and the US Department of Energy to advance CCHP adoption by manufacturing and supplying the most energy-efficient, high-performance heat pumps. “We are confident that together we can help reduce greenhouse gas (GHG) emissions, improve air quality and protect the environment for future generations.”
Nolte added: “Heat pumps are an important technology that can help reduce greenhouse gas emissions and combat climate change, and there is more work to be done to determine the proper performance of heat pumps in cold climates and to advance the technology as a whole.” The program provides “This is an incredible opportunity to start addressing these challenges in partnership with the US Department of Energy. The urgency of climate change requires us to be bold, innovate, disrupt, and most importantly, collaborate.”
Joanna Turpin is a senior editor. She can be contacted at 248-786-1707 or email joannaturpin@achrnews.com. Joanna has been with BNP Media since 1991, initially heading the company’s technical books department. She holds a bachelor’s degree in English from the University of Washington and a master’s degree in technical communications from Eastern Michigan University.
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