An alternate system uses a fog or great mist injected in to the intake air stream. Although many commercial systems can be found, growers can assemble and set up their own system using a ruthless piston pump and fog nozzles. The essential components are shown in Fig. 1. A two-stage 
system managed by a two- stage thermostat enables more water to be employed on excessively warm, shiny days. Temperature settings ought to be 5-10°F apart.
Algae development in the pads may become a problem which will reduce the effectiveness of the machine and result in accelerated deterioration of the pads. The addition of an algaecide to the drinking water supply can help in control.
It is desirable, especially in hard drinking water areas, to add a wetting agent to the water to obtain additional uniform wetting of the pads. A commercial materials or liquid household detergent at the rate of 2 tablespoons per 100 gallons can be used.
Water for the pads ought to be clean and lower 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 gallon each and every minute per linear foot of pad system should be provided to make certain adequate wetting.
In the most common coolant system (fan and pad), the fans draw air through wet pads that prolong the length of 1 endwall or sidewall. Aspen and covered cellulose are normal pad materials that always have life of 1 to three years. Approximately one square foot of pad are is needed for 20 square feet of floor area.
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