Analysis and application of air-to-air total heat exchanger to a dry fan-coil unit

At present, the fan-coil unit in China commonly works under wet cooling conditions in summers, which has certain disadvantages. Dry fan-coil unit, however, as an air conditioning system to be worthy of promotion, still has difficulty in dealing with fresh air with a big enthalpy difference. Air-to-air total heat exchanger (THX) is an efficient heat recovery device with capability of reusing the energy in return air. It is therefore increasingly applied to ventilation and air conditioning systems. In this research, three typical cities representing three different architectural thermal districts respectively were selected to make a comparison calculation of air conditioning systems in summers. The air conditioning effects with and without an air-to-air THX were compared. The calculation results show that pretreatment of fresh air using THX proves to be an effective measure to solve the problems along with the dry fan-coil unit, and meanwhile to reduce energy consumption of fresh air unit.