An alternate system runs on the fog or great mist injected into the intake air stream. Although a number of commercial systems can be found, growers can assemble and install their own system using a ruthless piston pump and fog nozzles. The basic components are shown in Fig. 1. A two-stage system controlled by a two- stage thermostat allows more water to be applied 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 result in accelerated deterioration of the pads. The addition of an algaecide to the drinking water supply will help in control.
It really 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 material or liquid home detergent at the price of 2 tablespoons per 100 gallons can be used.
Water for the pads ought to be clean and lower in Greenhouse Exhaust Fan mineral content to prevent clogging and coating of the pads. A pump, pipes and gutters are used to recirculate the drinking water. A flow rate 113 gallon each and every minute per linear foot of pad program should be provided to make certain adequate wetting.
In the most typical coolant system (fan and pad), the fans draw air through wet pads that lengthen the length of one endwall or sidewall. Aspen and covered cellulose are common pad materials that always have life of one to 3 years. Approximately one square foot of pad are is necessary for 20 square feet of floor area.