The pad & fan cooling greenhouse system cools down temperature, using evaporative cooling. On hot summer days, this is an efficient way to cool small greenhouses, keeping the plants in the best climatic conditions. In addition, this system uses exhaust fans to absorb air from outside into the greenhouse.
Firstly, the air is blown through the pad, which constantly evaporates water, creating a cooling effect. Then, the fans blow the cool air into the greenhouse, resulting in an overall decrease in temperature.
Some greenhouses need to be cooled at night, mainly in tropical regions. However, the wet pad and fan system may not provide the desired results in tropical regions, where absolute humidity is often high at night.
When outside conditions are humid, pad and fan system will lose its efficiency and provides less cooling capacity. This is because evaporative cooling is based on the difference between outdoor and indoor conditions.