PTCS Subcommittee Recommendations

ARHI Certification for Standalone Heat Pump Commissioning and Controls Measures

ANDSimplified Heat Pump Sizing Method

ANDDuct Sizing

Regional Technical ForumMay 5, 2009

Subcommittee Meeting• April 24, 2009• Attendees

– Dave Brook– Bruce Manclark– Mark Johnson– Rod Street– David Hales– Sarah Moore– Andres Morrison– Bob Davis– Mark Jerome– Adam Hadley– Brady Peeks (toward the end)

Standalone Commissioning & Controls

Recommendations1. Measure only applies to new heat pumps– Measure does not apply to existing heat pumps– “New heat pump” is defined as (at minimum) a new outdoor unit2. Systems must have an ARHI certificate– This may cause a new air handler and/or indoor coil to be

required.

Rationale: Without the ARHI certificate, it’s not possible to know the capacity of the heat pump with any certainty. Knowledge of the capacity and subsequent proper sizing is essential to ensuring the longevity of the outdoor thermostat and energy savings.

Heat Pump Sizing MethodRecommendation• A simplified “Pen & Paper” sizing method should be allowed

– Will maintain the integrity of the heat pump sizing calculator (which is currently available as a sizing option)

– Caveats to using the Pen & Paper method (otherwise, use Manual J)• Assumes sealed & insulated ducts• House must have insulation in walls, floors, and attic• Does not calculate cooling load

– Will be incorporated into the PTCS Heat Pump forms

Rationale: Although the heat pump sizing calculator is simple, it requires separate steps than the PTCS heat pump form. There is still some confusion about sizing requirements and inconsistencies in verifying proper sizing. Incorporating this simplified method into the heat pump form will allow the PTCS Service Provider to track and verify heat pump sizing.

(Additional Note: A change in standards may be warranted. Currently, the PTCS Service Provider Standards do not require service providers to collect sizing information; and the Heat Pump Installation Standards call for submitting sizing information to utilities, not the Service Provider.)

Duct Sizing, Lack of AirflowRecommendation• No change recommended

– If a house’s ductwork is causing insufficient airflow across the heat pump coil, either the ductwork should be improved ($$$), or the system will not qualify for PTCS certification.

Rationale: Without airflow, capacity and efficiency suffer. Without capacity, the outdoor thermostat and overall system efficiency suffer. PTCS heat pumps have proper airflow.

Additional Note: BPA will look into methods of educating consumers on the importance of proper airflow and that their duct system may need improvements in order for a heat pump to operate properly.