How to Stop Your Air Cooler From Smelling Bad & Blowing Hot Air

Evaporative Cooling Basics

An air cooler works by drawing warm dry air through wet woodwool or honeycomb pads. As water evaporates from the pads, it cools the air. If the pads are dry, or the water is stagnant, the cooler fails to function and releases a terrible smell.

Why is the Cooler Smelling Bad?

Stagnant water in the cooler tank becomes a breeding ground for algae, mold, and bacteria (specifically Legionella). Over time, the honeycomb pads absorb this dirty water and emit a swampy, rotting odor when the fan runs. Cleaning the tank and adding a drop of mild disinfectant is essential.

Why is it Blowing Hot Air?

If the air isn't cold, check if the water pump is running. Submersible pumps are prone to getting jammed by lime-scale deposits from hard water. If the pump impeller is seized, no water reaches the pads, leaving them dry. The fan just circulates warm room air.