18 May 2017

P.3.1.2 Comprehensive Analysis of Exhaust Air Heat Pump Heat Recovery Efficiency in Dedicated Outdoor Air System

Exhaust air heat recovery is an important energy saving technology in buildings, which reduces energy consumption on thermal and humid processing of outdoor air. Dedicated outdoor air system with exhaust air heat pump (EAHP) is a newly developing technology, which efficiently recovers waste energy from exhaust air through vapor-compression refrigerant cycle. Some manufacturers claimed that the thermal recovery efficiency of EAHP has been over 100% and is superior to that of the enthalpy wheel total heat exchanger. This paper numerically simulates and compares the performance of both EAHP and enthalpy wheel under different application conditions. The results reveal that the EAHP can recover more waste energy than the enthalpy wheel, but less energy-efficient in the whole dedicated outdoor air system. However, EAHP is still very promising because of its smaller installation size, much wider application temperature range, and no cross-contamination between outdoor air and exhaust air.