24 June 2014

On-Site Performance of Air Source Heat Pumps

A pilot project consisting of 22 test sites was carried out in Quebec, Canada during the heating season to measure the energy savings associated with the use of heat pumps for space heating. The sites participating in the project were divided into three different
categories according to their respective space heating system. Sixteen sites were equipped with an air handling unit with a built-in heat pump (10 sites with a single stage air source heat pump and 6 sites with a cold climate air source heat pump (5 variable speed compressors and 1 two-stage)) assisted by an electric coil in the unit. The remaining 6 sites were equipped with a ductless split heat pump system supplemented by independent electric
baseboard heaters. Monitoring was conducted for 21 months (from September 2011 to May 2013). The results show that the performance of a single stage heat pump provides similar energy savings regardless of their capacity. The energy savings of these heat pumps were about 28%
compared to the heating demand. For heat pumps designed for cold climates it was found that these systems are more efficient than the single stage heat pump systems. The energy
savings of these heat pumps were about 45% compared to the heating demand. For the ductless heat pumps, which operate with the same technology as cold climate heat pumps, energy savings of 25% were attained, compared to the heating demand.