Evaporative coolers have many advantages over air conditioning systems. They are cheaper to purchase and run, more environmentally friendly, and because they are less mechanically complex than air conditioners, they are usually more reliable.
Unfortunately, evaporative coolers can still suffer from problems from time to time, and an unpleasant smell coming from your cooler may be a sign of underlying issues.
Why Does Your Evaporative Cooler Smell Musty Or Fishy?
Evaporative coolers function by passing air over and through absorbent pads saturated with water. These moistened pads take some of the heat out of the air and also make the air passing through the cooler slightly more humid, providing relief from both heat and dryness during hot summer days.
Because air is constantly passing over and through the pads while the cooler is functioning, they can pick up a lot of unwanted dirt and debris from the air. Dust, pollen, air pollution particles and other unpleasant particulate matter will accumulate in the pads over time.
A moist, dirty evaporative cooler pad can subsequently become a breeding ground for bacteria, which create foul-smelling chemicals as they feed and reproduce. If your evaporative cooler is generating cool air that smells musty or fishy, the pads are probably dirty and filled with bacteria.
If the pads were installed relatively recently, running the evaporative cooler on fan only mode for a few days will dry out the pads and kill the bacteria causing the smells. Fresh water can then be added to the pads. Bear in mind your cooler will not generate any cool air while it is in fan-only mode.
However, if your cooler has been using the same pads for a long time, they are probably too dirty for drying out to fix the odour issues. Replace the pads yourself, or have them replaced professionally by an evaporative cooler repair service. If your evaporative cooler is fitted to your home's roof, professional replacement is safest.
What If Fitting New Pads Doesn't Help?
New evaporative cooler pads usually create an odd smell when they are newly fitted, but this smell will go away within a day or two. If you have fitted new pads very recently, but they are already starting to smell musty or fishy again, it could indicate problems with your evaporative cooler's airflow.
Bacteria breed more rapidly in poorly ventilated areas. If they are breeding quickly enough in new pads for the cooler to start smelling again quickly, it is likely that not enough air is passing through the cooler.
Airflow problems will also undermine the cooler's cooling power, and can be caused by mechanical problems with the cooler's fans, fan motors or exhaust vents. Call in a repair service to inspect and fix the cause of the airflow issue.
What If Your Evaporative Cooler Makes A Burning Smell?
If the air coming from your evaporative cooler smells like burning rubber or plastic, deactivate it as soon as possible and call in a professional repair service.
This burning smell can be caused by serious problems with your cooler's electrical control board or wiring, or may be caused by a fan or pump motor burning out. These problems can cause catastrophic damage or start a fire if they are ignored, and must be rectified before the cooler can be used safely.