Clean Heating & Cooling Reports

NYSERDA and partners have conducted several studies on the performance of heat pumps at sites located within New York State. Below is a summary combining the most recent findings of the studies. Each study represents subject projects that took place within differing timeframes, targeting a variety of market segments, and operating under varying program rules. This summary includes the following studies:

Heat Pump Impact Evaluation [PDF], DNV, 2022, 122 sites
Hudson Valley Heat Pump Pilot (HVHPP) Program [PDF]: Demonstrating the Emerging Technology of Cold-climate Air Source Heat Pumps, NYSERDA, 2022 (Report Number 22-08), 20 sites
Replacing Fossil Fuel Heat with Mini-Split Heat Pumps in Urban Housing Stock [PDF], NYSERDA, 2022 (Report Number 22-04), 20 sites
Residential cold-climate Air Source Heat Pump Building Electrification Study [PDF], Cadmus, 2022, 43 sites in NYI

Except for the NYSERDA Heat Pump Program Impact Evaluation, which included 122 sites, the number of sites included in other studies are too small to achieve mathematical, statistical significance. However, taken as a body of research across the total 181 New York sites, the results are generally consistent, and the insights provide guidance to support the growth of heat pumps.

The installations that were included in these studies were not all installed at the same time. Installations in the studies listed were completed between 2018 and 2020. Findings were impacted by the COVID-19 pandemic, including study site selections, total customer energy usage, and more. Importantly, we are still learning about heat pumps, including:

Heat pump performance can vary over a single heating season based on equipment model and type. For example, some cold-climate air source heat pumps (ccASHPs) are very good at maintaining capacity at very low temperatures, reducing the need for supplemental heat but the same equipment might lose efficiency in milder temperatures, while a different brand and model of equipment might do the opposite making it important to consider these seasonal performance tradeoffs when selecting specific equipment for specific projects.
Where back-up heating may still be recommended in New York State and how envelope improvements and integrated controls can be leveraged to improve performance and results
Heat pump performance for meeting customer water heating needs (e.g., heat pump water heaters)

As further studies are published, this summary will be updated.

Summary of Findings

Performance

Finding: Cold-climate air source heat pumps (ccASHPs) and ground source (geothermal) heat pumps, when designed and sized to meet the building’s heating load, provide adequate heating, cooling, and comfort in New York State within expected efficiency ranges.

Supporting or clarifying statements from the reports

“Overall average ccASHP system seasonal heating performance of 2.39 sCOP was in line with results from other studies, with slightly higher metered performance for whole-home systems.”
“Ground source heat pumps performed at near rated efficiencies.”
“The heat pumps worked. Only 1 of 43 customers reported that the heat pumps didn't heat enough when it was cold outside.”

Related NYS Clean Heat Actions

NYSERDA has collaborated with NEEP on a cold-climate heat pump equipment selection support tool to ensure sufficient heating in cold weather and efficient heating year-round.
NYS Clean Heat will continue to require Cold Climate ASHP Sizing and Design Training for all new participating contractors to support meeting heat pump performance expectations. The utilities will require existing contractors to take Cold Climate ASHP Sizing and Design Training as of March 1, 2023.

Satisfaction

Finding: New York State homeowners who installed heat pumps are generally satisfied with them and report improved comfort as a key benefit.

Supporting/clarifying statements from the reports

“The homeowner surveys indicated that most homeowners were satisfied with the heat pump system.”
“On average, participants reported very high satisfaction levels with heating and cooling performance.”

Related NYS Clean Heat Actions

NYS Clean Heat marketing promotes cases studies of satisfied customers.
Improving comfort, health, and safety of the home are secondary benefits promoted in NYS Clean Heat marketing.

Energy Consumption

Finding: Homeowners decrease their heating fuel consumption through the installation and operation of heat pumps when heat pumps are sized to meet the full heating load of the home.

Supporting/clarifying statements from the reports

“On average fossil fuel use for space heating was reduced by 86%.”
“ccASHP’s displaced 34-100% (average 85%) of the fuel used by the original system.”

Related NYS Clean Heat Actions

Displacing fossil fuel (oil, propane, natural gas) use is the primary goal of NYS Clean Heat.

Heating Bill Implications

Finding: Homeowners with existing heating systems that use electric resistance heat or delivered fuels save the most money, but all get comfort and health benefits.

Supporting/clarifying statements from the reports

“A customer’s existing fuel type is an important factor to cost effectiveness. Natural gas customers will likely see overall utility bills increase by switching to electric ccASHP systems for heating due to the high cost of electricity relative to natural gas in the Northeast.”
“Because electricity is more costly per unit of energy than natural gas, electrification [can] result in higher utility bills for space heating, even when heat pumps are operating efficiently, [especially] in the New York City region.”

Related NYS Clean Heat Actions

Given current fuel and electricity prices, displacing delivered fuel use is the initial focus of NYS Clean Heat as it results in maximum customer cost savings at this time.
Improving comfort, health, and safety of the home are secondary benefits promoted in NYS Clean Heat marketing.

Role of Weatherization

Finding: Improving the home’s thermal performance increases energy savings and occupant comfort.

Supporting/clarifying statements from the reports

“Increasing the emphasis on insulation and air sealing can reduce the perceived impact of electrification by reducing overall heat demand.”
“Respondents who installed weatherization measures were significantly more likely to see a decrease [in energy bills] compared to respondents who did not install weatherization.”

Related NYS Clean Heat Actions

Programs like the NYS Clean Heat Statewide Heat Pump Program and NYSERDA’s Comfort Home and EmPower+ programs encourage/require improving building performance before or at the same time as installing heat pumps.

User Behavior

Finding: Energy savings won’t be fully realized unless heat pumps are used by homeowners as originally intended: optimize heat pump use first and prioritize over fossil fuel equipment.

Supporting/clarifying statements from the reports

“Most participants continued to use pre-existing HVAC systems. These partial displacement scenarios reduce the achievable savings.”
“In one of the studies, at three of the twenty homes, the heat pumps were used initially, but then the homeowners reverted to relying more on the fossil fuel boilers in subsequent seasons – reportedly due to comfort concerns.”

Related NYS Clean Heat Actions

NYS Clean Heat marketing, program incentives and customer education emphasizes using heat pumps to maximize fuel use reduction NYSERDA has developed “leave-behind” reference material to help customers optimize the operation of their heat pump when a fossil fuel system is also available.

User Training

Finding: Contractor training on sizing, design, and equipment selection and accompanying customer education on system operation are key to ensuring energy savings are realized.

Supporting/clarifying statements from the reports

“Contractors were a key knowledge conduit, as contractors were how most customers learned how to use their ASHP. 93% of respondents reported the contractor helped them understand how to use the new system, with 80% of respondents reporting that contractors provided leave-behind materials.”
“Contractors were given customer-facing materials to optimize heat pump operation.”

Related NYS Clean Heat Actions

NYS Clean Heat will continue to require Cold Climate ASHP Sizing and Design Training for all new participating contractors to support meeting heat pump performance expectations. The utilities will require existing contractors to take Cold Climate ASHP Sizing and Design Training as of March 1, 2023.
Clean Heat Connect is a dedicated NYSERDA effort to expand the skills of heat pump contractors to properly size, design, select, sell, and maintain heat pump systems.
The NYSERDA funded NEEP ccASHP equipment selection tool .