No—evaporative coolers require proper ventilation to work effectively. This is one of the key differences between evaporative cooling and air conditioning.
Why ventilation is essential:
Evaporative coolers continuously add moisture to the air. Without an exhaust path, humidity quickly builds up inside your home, making the air feel muggy and uncomfortable rather than cool. The humid air must escape so fresh, dry air can be drawn through the cooler.
How to ventilate properly:
1. Open windows or doors on the opposite side of your home from where cool air enters 2. Create cross-ventilation by opening windows in rooms you want to cool 3. Crack windows 2-4 inches in each room—you don't need them wide open 4. Use the "relief" path - if your cooler has a central duct, open windows in distant rooms to pull cool air through the house
Ventilation tips:
- Open windows equal to about 1-2 square feet per 1,000 CFM of cooler capacity
- Open windows on the shady side of the house when possible
- Close windows in rooms you're not using to direct airflow where you want it
- On very hot days, you may need more ventilation
Unlike air conditioning, which works in a sealed, recirculating system, evaporative cooling is a one-way flow: hot air in, cool air out, humid air exhausted.
