An alternate system runs on the fog or great mist injected in to the intake air stream. Although several commercial systems can be found, growers can assemble and install 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, bright days. Temperature settings ought to be 5-10°F apart.
Algae growth in the pads can become a problem that may reduce 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 water areas, to add a wetting agent to the water to obtain more uniform wetting of the pads. A commercial materials or liquid household detergent at the rate of 2 tablespoons per 100 gallons can be used.
Drinking water for the pads ought to be clean and low 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 per minute per linear foot of pad system 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 prolong the length of one endwall or sidewall. Aspen and coated 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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