Virtual – NEEA Low-Load Efficient Heat Pump Research

Microsoft Teams meeting

Modeling and lab testing revealed that some heat pumps work significantly better under part-load (low-load) conditions, resulting in significant annual energy savings with little to no differentiation in retail price.  NEEA contracted with Cadeo Group and Optimized Thermal Systems to better understand why and what equipment hardware or design changes are needed to achieve top quartile low-load efficiency.

The project involved two parts: 1) explore why. If the NEEP-published minimum capacity COP at 47 degrees is a good indicator of low-load efficiency, why isn’t this value reflected in the federal test procedure for HSPF2 or SEER2? And 2) the second part was to conduct a detailed virtual “paper” tear-down of many different heat pump systems to determine the source of low-load efficiency and what, if any, hard costs can be associated with such systems.