Critique of improved performance of air-cooled chillers with evaporative cooling.

This article examines how evaporative cooling helps improve the energy performance of air-cooled chillers installed in refrigeration and central air-conditioning systems. Precooling of condenser air for heat rejection can be done by direct evaporative coolers and mist generators. The refrigeration effect and coefficient of performance of the chillers can be enhanced in various degrees by the devices under different outdoor conditions. Mist generators are more preferable because of their flexibility in retrofitting in existing chillers, the negligible flow resistance by mist and higher cooling effectiveness with limited water use. A higher difference between the dry bulb and wet bulb temperatures in future climates would call for a wider application of evaporative cooling for air-cooled chillers for sustainable development. Discussion has been given on how the mist generation rate should be regulated to complement condenser fan control. More research should be conducted to develop a mist nozzle layout to maximize cooling effectiveness while optimizing the control of condensing temperature for maximum performance.