The environment of a greenhouse can become too hot for healthy plant production even in the winter. On the other hand, extra cooling beyond what fan ventilation can provide may be necessary during the summer. A fan pad is a tool that can be used to reduce greenhouse temperature. A fan pad is a system that uses an exhaust fan to pull air through evaporative cooling pads. Cooling pads create a large amount of surface area that is exposed to air being drawn into the greenhouse by exhaust fans and this area allows for quick evaporation.
The deduction in air temperature occurs around the exhaust side of the cooling pad; air can easily pick up over 8 to 9 degrees Fahrenheit even in a well-designed greenhouse. However, cooling pads are not able to achieve a hundred per cent efficiency but fan and pad systems need to be sized appropriately to achieve the maximum cooling efficiency. The cooling pad needs regular maintenance to remain efficient if any algae or mineral build-up, can reduce air movement and lower efficiency.