The following specification defines a set of performance requirements and reporting requirements to meet the voluntary “Cold Climate Air Source Heat Pump Specification” (ccASHP Specification). The specification was designed to identify air-source heat pumps that are best suited to heat efficiently in cold climates (IECC climate zone 4 and higher). The specification is intended as a model equipment specification to be used broadly by energy efficiency program administrators in cold climates as a minimum requirement for program qualification. It also is intended for engineers, contractors, and other practitioners who need assurance that the equipment they select will serve the load efficiently throughout the ambient temperature range, and to differentiate cold climate performance.