An alternate system runs on the fog or good mist injected into the intake air stream. Although several commercial systems can be found, growers can assemble and set up their own system utilizing a ruthless piston pump and fog nozzles. The basic components are demonstrated in Fig. 1. A two-stage system controlled by a two- stage thermostat allows more water to be applied on excessively warm, shiny days. Temperature settings ought to be 5-10°F apart.
Algae development in the pads can become a problem that may reduce the effectiveness of the system and result in accelerated deterioration of the pads. The addition of an algaecide to the water supply will help in control.
It is desirable, especially in hard water areas, to add a wetting agent to the water to obtain additional uniform wetting of the pads. A commercial material or liquid home detergent at the price of 2 tablespoons per 100 gallons may be used.
Drinking water for the pads ought to be clean and low in mineral content to prevent clogging and coating of the pads. A pump, pipes and gutters are accustomed to recirculate the water. A flow rate 113 Greenhouse Auto vantilasyon gallon each and every minute per linear foot of pad program should be provided to make certain adequate wetting.
In the most common cooling system (fan and pad), the fans draw air through wet pads that expand the length of 1 endwall or sidewall. Aspen and covered cellulose are normal pad materials that usually have life of one to 3 years. Approximately one square foot of pad are is needed for 20 square ft of floor area.