Disadvantages of Evaporative Coolers

Maintenance

• Evaporative coolers need regular maintenance throughout the season to run efficiently. Coolers have moving parts including the motor pulley that turns the fan to pull air through the wet pads. The motor's shaft needs lubrication throughout the season to reduce wear caused by friction. While routine maintenance for the coolers is not complicated, coolers often sit on roofs, complicating maintenance.

Parts

• Parts on evaporative coolers need replacing from time to time. The pads last a season, or even two in places where water is not excessively hard. The belt that turns the pulley can fray and break. Coolers also rely on water pumps to circulate the water to the pads. If the pump breaks while the resident is away, the cooler continues to run, blowing hot air throughout the home or building. If the water stops running to the cooler, the pump can burn out.

Inefficient in Humidity

• Evaporative coolers are not efficient when the humidity level is high. When the dew point, a combination of temperature and humidity, goes over 55 degrees Fahrenheit, coolers work less effectively and not at all when it rains. If humidity levels get too high, mold can grow in the house.

Structural Considerations

• Water is a big component in an evaporative cooler, and should the unit start to leak, the water can do damage to roofs. Wall or window coolers can also do damage to the building's structure. Coolers can also create salt damage on the roofs. People who use bleed-off hoses to reduce salt buildup in a cooler can damage plants and soil around the coolers since the water has a high concentration of dissolved mineral solids that can render soil infertile.