Year round experimental study on a constant temperature and humidity air-conditioning system driven by ground source heat pump

Numerous studies about the ground source heat pump building heating and cooling systems have been constructed in office building, hotel, residential building and school et al. However, few researches about the constant temperature and humidity air-conditioning system driven by ground-coupled heat pumps were carried out. In this paper, a constant temperature and humidity air-conditioning system driven by ground source heat pump was designed and constructed in an archives building in Shanghai, China. During the operation in the cooling mode, the heat extraction from the condenser of the heat pump was divided: part was rejected to the soil while another was used to reheat the air in AHUs. According to the experimental results, the indoor temperature and relative humidity fulfilled the “Archives Design Code”. In summer, the heat rejected to the soil was reduced by 32%, which was helpful for the earth energy conservation. The soil temperature increased only 0.5 °C after the GSHP system operating for a year. The energy cost of the air-conditioning system was 56.1 kWh/m2. Compared with air source heat pump system and water cooled unit with boiler system, the operating cost of ground source heat pump was reduced by 55.8% and 48.4%, respectively.

Research highlights
► A constant temperature and humidity system was driven by GSHP, which was hardly constructed in such system.
► Experimental results about the performance of the GSHP system in a whole year including spring and autumn were presented.
► In summer, the heat rejected to the soil was reduced by 32% according to the heat recovery.
► A comparison of the GSHP system with conventional systems applied in the same situation was presented by experimental results.