ABSTRACT
Cooling is considered as the basic necessity for greenhouse crop production in tropical and sub-tropical regions to overcome the problems of high temperatures during summer months. Development of suitable cooling system that provides congenial micro-climate for crop growth is a difficult task as the design is closely related to the local environmental conditions. The air will be at its lowest temperature immediately after passing through the pads. Fog is generally produced using a high pressure pump to atomize water by forcing it through fixed nozzles attached to the tips of rotating fan blades or similar arrangement. Atomization may also be accomplished by a rotating disk or acoustic oscillator. Roof evaporative cooling is achieved by sprinkling water onto the surface of greenhouse roof so as to form a thin layer of the free water surface causing increase in the evaporation rate and to fall the wet bulb temperature of the closely surrounded air.
