Development of Photocatalytic Condensate-Recovery Air-Conditioning System for High Energy Efficiency and Good Indoor Air Quality

Conventional air-conditioning systems produce a considerable amount of cold condensate due to the dehumidification of air below the dew point. The condensate is commonly drained as thermal loss.In this project, the coefficient of performance (COP) of an air-conditioning system is improved by recovering the thermal energy (i.e. cooling) of the condensate. The condensate will be circulated to a packing medium where air in direct contact with the condensate is pre-cooled by means of evaporative and convective cooling. Good indoor air quality (lAQ) is another advantage as the air is washed by the condensate and leaves the system with low concentration of suspended particulates and airborne microorganisms.The circulating condensate will become contaminated as it removes and collect pollutants from the air treated. Photocatalysis is a promising technology for treatment of the condensate. The recent technological development has shown that titania (TiO2) nanotube-array thin films can perform effective water purification.Combining the above features, photocatalylic condensate-recovery air-conditioning systems can make a significant improvement in energy efficiency and IAQ.