An alternate system uses a fog or good mist injected into the intake air stream. Although a number of commercial systems are available, 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 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 decrease the effectiveness of the machine and lead to 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 water areas, to include a wetting agent to the water to obtain more uniform wetting of the pads. A commercial materials or liquid home detergent at the rate of 2 tablespoons per 100 gallons may be used.

Water for the pads should be clean and low in mineral content to prevent clogging and coating of the pads. A pump, pipes and gutters are used 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 cooling system (fan and pad), the fans draw air through wet pads that expand the length of 1 endwall or Greenhouse Auto Vent sidewall. Aspen and coated cellulose are normal pad materials that usually have life of one to 3 years. Approximately one sq . foot of pad are is necessary for 20 square ft of floor area.