An apparatus and method to cool compressors, condensing coils, and similar devices. The compressor or condensing coil is cooled by the delivery of water, which may be ambient temperature or chilled. In one embodiment, the water is delivered to a mesh filter or screen via one or more mist spray nozzles. Water conduits may be integrated with the filter frame. The method to control the delivery of the water is designed to conserve water. The control circuit comprises a microcontroller device which contains programming that receives inputs, including but not limited to, outside ambient air temperature, condenser liquid line temperature, relative humidity and electric current, and uses said inputs to provide a stepwise level of control (“solenoid open time”) of water delivery commensurate with outside air temperature and relative humidity.