An alternate system uses a fog or good mist injected in to the intake air stream. Although a number of commercial systems are available, growers can assemble and set up their own system using a high pressure piston pump and fog nozzles. The essential components are demonstrated in Fig. 1. A two-stage system managed by a two- stage thermostat enables more water to be applied on excessively warm, shiny days. Temperature settings ought to be 5-10°F apart.

Algae development in the pads may become a problem that may decrease the effectiveness of the system and lead to accelerated deterioration of the pads. The addition of an algaecide to the drinking water supply will help in control.

It is desirable, especially in hard drinking water areas, to add a wetting agent to the drinking water to obtain additional uniform wetting of the pads. A commercial materials or liquid home detergent at the rate of 2 tablespoons per 100 gallons can be used.

Water for the pads should be clean and lower in mineral content to avoid 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 program ought to be provided to make certain adequate wetting.

In the most typical coolant system (fan and pad), the fans draw air through wet pads that extend the length of one endwall or sidewall. Aspen and covered cellulose are normal pad materials that always have life of one to 3 years. Approximately one square foot of pad are is needed for 20 square feet of floor area.

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