Applicability of air-to-air heat recovery ventilators in China

In the past two decades, increased urbanization and industrialization have caused a tremendous rise of the energy consumption of buildings in China, and a corresponding need is to save this energy. Energy recovery ventilation systems can save substantial amounts of HVAC energy by recovering otherwise wasted energy from the exhaust air to precondition intake air. In China, the minimum global heat recovery efficiency is prescribed by a national design standard, i.e., GB50189-2005, for the heat recovery equipment in public buildings. Because of the local climate differences between southern and northern regions in China, the fractions of sensible and latent heat in per unitary flow rate of fresh air are different from each other in the regions, so is the global effectiveness of a heat recovery system. Considering four different climate zones in China, the annual composition of energy consumption of fresh air for per unitary flow rate is evaluated by employing the testing data of climatic parameters in the eight selected cities. An investigation on the choice of heat exchangers for the energy savings in buildings with little moisture emissions is carried out, and the analysis gives the applicability of air-to-air heat exchangers in China for different operations in order to copy with the prescribed by the standard.