Qualifying Air Source Heat Pump in the APS

The eligibility criteria and requirements for qualifying an air source heat pump system in the Alternative Energy Portfolio Standard.

Eligibility Criteria

All Renewable Thermal Generation Units must:

  • Generate useful thermal energy using sunlight, biomass, biogas, biofuel or naturally occurring temperature differences in ground, air or water
  • Deliver a useful thermal load to a facility located in Massachusetts
  • Have an operation date January 1st 2015 or later

An air source heat pump uses compression and evaporation to transfer thermal energy from the ambient air to a thermal load as Useful Thermal Energy. There are several requirements in order for air source heat pump Generation Units to be eligible.  For a list of eligibility requirements, please see the APS regulations, beginning on page 19. Please note while utilizing air source heat pumps for cooling is allowed, only the Useful Thermal Energy used for heating is eligible to generate AECs. 

To submit a Statement of Qualification application (SQA), please visit the APS Renewable Thermal Application Portal.

For more information on renewable thermal in the APS, please visit our APS Statement of Qualification webpage.

Size Classification and Multipliers

The size classifications for air source heat pump Generation Units are as follows:

TechnologySmallIntermediateLarge
Air source heat pump; electric motor or engine drivenOutput capacity less than or equal to 134,000 Btu per hourOutput capacity between 134,000 and 1,000,000 Btu per hourOutput capacity greater than or equal to 1,000,000 Btu per hour

The multipliers for air source heat pump Generation Units are as follows:

TechnologySmallIntermediateLarge
Air source heat pumps (electric or engine driven) –supplying less than 100% of building heating load2--
Air source heat pump (electric or engine driven) –all other333

For small ASHP Generation Units to be eligible a multiplier of three, the Generation Unit must supply 100% of a building’s total annual heat load and if it is installed in an existing building, the non-renewable heat source must be removed.

In addition to the above multipliers, any air source heat pump installed in a building shall be eligible for an additional multiplier of 2 (added to the base multiplier) if the building meets any of the following criteria:

  • achieves Home Energy Rating System (HERS) rating of 50 or less
  • meets the Department of Energy definition of “Zero Energy”
  • achieves PHIUS+ Certification by the Passive House Institute US (PHIUS)
  • registers as a Certified Passive House Building or an EnerPHit Retrofit by the International Passive House Association (iPHA)

More information on these multipliers can be found in the Guideline on Multipliers for Renewable Thermal Generation Units.

Small air source heat pump Generation Units

Eligibility Criteria

An air source heat pump uses compression and evaporation to transfer thermal energy from the ambient outdoor environment to a thermal load as Useful Thermal Energy. To be eligible, an air source heat pump Generation Unit must be:

  • ENERGY STAR™ certified
  • meet the Cold Climate Air Source Heat Pump Specification Version 2.0 published by Northeast Energy Efficiency Partnerships effective January 1, 2017 or any version thereafter
  • have a variable speed compressor
  • be part of an Air-Conditioning, Heating, & Refrigeration Institute matched system
  • have a coefficient of performance greater than or equal to 1.9 at Max Heating Capacity at 5 degree Fahrenheit and a coefficient of performance greater than or equal to 2.5 at Rated Heating Capacity at 17 degree Fahrenheit.

For a list of current APS eligible small ASHP, see the link below. The list is a summary of the air source heat pumps that are eligible for consideration under the Alternative Energy Portfolio Standard (APS). Each of the heat pumps listed have been reviewed to determine if they meet the system performance requirements of the APS. The list is not necessarily an exhaustive list of eligible heat pumps and is to be used for informational purposes only.

APS Eligible Small Air Source Heat Pumps - Updated September 2024

In new construction, all small ASHPs must supply 100% of a building’s total annual heat load; non-renewable supplemental heat sources are prohibited.

In existing buildings where an ASHPs supplies 100% of the building’s total annual heat load, the non-renewable heat source must be removed.

Air source heat pumps that supply less than 100% of the building heating load must:

  • be installed in existing buildings
  • be used as a primary heat source, providing at least 90% of the total annual heating load
  • be integrated to the building’s heating distribution system such that the useful thermal output of the RTGU is able to be distributed to all space-conditioned areas of the building
  • have a capacity at 5 degrees Fahrenheit that is at least 50% of the name-plate capacity of the existing heating source equipment

AEC Calculation

Small air source heat pump Generation Units are eligible for preminting, which allows the owner to receive 10 years of AECs upfront. After reviewing and approving the application for the Generation Unit, DOER will calculate the 10 year strip of AECs to be minted. The calculation is as follows:

More information on this calculation can be found in the Guideline on Metering and Calculating the Useful Thermal Output for Renewable Thermal Generation Units – Part 1 (Calculations for Small and Intermediate Generation Units).

Application Requirements

All small air source heat pump Generation Units are required to submit the following in their Statement of Qualification Application:

  • Site and facility information
  • Contact information
  • Equipment specifications
  • Design specifications
  • NEPOOL GIS information
  • AEC Service Agreement (optional, attachment)
  • Home Energy Rating System (HERS) certification (optional, attachment)
  • Affidavit of Zero Energy (optional, attachment)
  • Passive House certification (optional, attachment)

Intermediate and large air source heat pump Generation Units

Metering Information

Intermediate and large air source heat pump Generation Units will receive AECs, based on their metered production, on a quarterly basis. Generation Unit owners should review the Guideline on Metering and Calculating the Useful Thermal Output for Renewable Thermal Generation Units – Part 2 (Metering for Intermediate and Large Generation Units) for information on metering requirements.

Application Requirements

All intermediate and large air source heat pump Generation Units are required to submit the following in their Statement of Qualification Application:

  • Site and facility information
    • Site plan (attachment)
  • Contact information
  • Equipment specifications 
    • Equipment arrangement drawing (attachment)
    • Annotated product literature for all major equipment (attachment)
  • Design specifications
    • Description of system controls and sequence of operations (attachment)
    • A process flow diagram (attachment)
    • A one line electrical diagram (attachment)
  • NEPOOL GIS information
  • AEC Service Agreement (optional, attachment)
  • APS Renewable Thermal Performance Workbook (attachment)
  • Independent Verifier request form (attachment)
  • A metering plan including a list of meters (attachment)
    • Annotated product literature for each APS meter (attachment)
    • Annotated product literature for the Data Acquisition System (DAS) (attachment)
  • Certified Performance Data Construct (intermediate Generation Units only) (attachment)
  • System Information Data Sheet
  • Home Energy Rating System (HERS) certification (optional, attachment)
  • Affidavit of Zero Energy (optional, attachment)
  • Passive House certification (optional, attachment)

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