Performance Test of a Ground-Air Heat Exchange Fresh Air System for an Office Building in Tangshan

摘要

A fresh air system using ground-air heat exchangers (GAHEs) was built for an office building in Tangshan, and its actual performance during the operation period in summer and winter were tested and analyzed. Results showed that the present system was reliable. The maximum indoor CO_2 concentration ranged from 600-700ppm, satisfying the requirements of indoor air quality. For a typical operation condition, the underground heat exchange rate per the internal surface area of GAHEs reached 44.2W/m~2 in summer and 90.9W/m~2 in winter, and the corresponding daily average heat exchange efficiency was 0.72 and 0.84, respectively. The present results are useful for further optimization of GAHE systems built under similar climate conditions.