A new heat recovery technique for air-conditioning/heat-pump system

A new heat recovery technique for an air-conditioning/heat-pump (AC/HP) system is proposed in this paper. The new technique employs a compound air-cooling and water-cooling condensing module to replace the traditional sole air-cooling condensing module of the AC/HP system. The system adopting this technique can be called a multi-function AC/HP system. It can improve cooling and heating effects, and recover condensing heat for heating sanitary water. A fluid bypass pneumatic controlled reversing valve is also added to the system. It makes sure that the system can shift flexibly between different working modes according to the building users’ requirement. An experimental unit of the new technique AC/HP system has been made and tested. Testing results indicate that the new AC/HP system is able to perform stably and flexibly under various conditions. The system has relatively large coefficient of performance (COP) which can be as high as about 6.0. It is suggested that a supplementary electric heating device should be used to heat water to a higher temperature in the winter before starting sanitary water.