The studies described in this paper were initiated to characterize performance and operation of state-of-the-art air-source heat pumps in northern climate applications. Impetus was provided for this investigation by increasing interest in heat pumps for primary space heating service in northern parts of the U.S. Heat pumps have traditionally had limited acceptance in the north except in select regions, such as the Pacific Northwest.

This paper describes the field monitoring approach, general characteristics of the computer simulation model, and presents results obtained for the full year of monitored performance and select additional computer studies.