One of the best ways to cool a greenhouse in the summer is through a combination of reducing light intensity and ventilation. The amount of light reduction depends on the heat load in the greenhouse and the light requirements of the plants grown. Greenhouse whitewash, shade cloth, screens of wood or aluminum, or Venetian blinds can be used for shading. Shade cloth material can be used during the winter months for night heat retention.
Another method for cooling a greenhouse is evaporative cooling, which relies on air passing through a porous pad saturated with water. The evaporating water removes heat from the greenhouse. There are two types of evaporative coolers: fan-and-pad systems and unit coolers (swamp coolers).
