Experimental investigation of air-source heat pump for cold regions

Great advancements have been made in air source heat pumps (ASHP) due to concerns for water and consciousness of sustainable development; however there is still a serious shortcoming that limits their widespread applications, especially in sub-zero regions. This article proposes a new sub-cooling system employing a scroll compressor with a supplementary inlet which can effectively solve these problems. The prototype ASHP was validated and ran a whole winter in Beijing, China. The relevant dynamic-performance functions were tested and the outcomes show that this new kind of ASHP can work very well under ambient temperatures as low as −15 °C. In addition, the efficiency of the improved ASHP under all circumstances was addressed and great energy can be saved through the improved systemʹs increased efficiency. In this way the applications of ASHP were enlarged and a simple and feasible alternative heating service was developed for heating in north China which can also partly solve the severer and severer atmosphere pollution problems in these regions.