Evaporative cooling is a common greenhouse cooling system.

• A. True
• B. False
• C. Sometimes
• D. Never

Answer: (A)

Evaporative cooling reduces greenhouse air temperature by leveraging the energy absorbed when water evaporates. Air is passed through wetted pads or sprayed into the space, and as water changes to vapor it draws heat from the air, cooling it. This method is simple, energy-efficient, and inexpensive compared with mechanical cooling, so it’s widely used in many greenhouses, especially in hot, dry climates. It also increases humidity, which can be beneficial for some crops but may raise disease risk if not managed. Because its cooling effectiveness depends on low ambient humidity, it’s not equally effective everywhere, but overall it’s a common greenhouse cooling approach.