Abstract
A hot-water supply system was constructed to utilize wasted heat of an air-conditioning system with HFC134a refrigerant. A desuperheater was equipped ahead of the condenser of an air-conditioning machine to extract thermal energy of compressed high-temperature refrigerant. HFC134a was selected as refrigerant because its pressure was relatively lower at higher temperature. The required refrigerant charge was investigated and performance of the air conditioning system with/without a desuperheater was compared to assess the effect of installing a desuperheater. It was concluded that the required refrigerant charge increased by installing a desuperheater, and that the ability of cooling heat exchange was similar for both with/without a desuperheater with required refrigerant charges. It was also shown that cooling COP decreased 15% by installing a desuperheater, because the work done by the compressor increased, but the overall energy efficiency including cooling and hot-water supply increased 34%.
