Run it dry before boxing it away
Any appliance with a water tank or pad — an evaporative cooler especially — should run on fan-only or sit open for a few hours to dry out fully before storage. Trapped moisture under a cover, against a warm motor housing, is a common and avoidable cause of corrosion and mold over an off-season.
Empty every tank, completely
A tank left even partly full for months is stagnant water sitting in a warm, dark space — exactly the conditions that grow mold and odor. Empty, rinse, and dry every reservoir before storage, not just the ones that look obviously wet.
Clean the filter before storing, not after
Cleaning a fan’s dust guard or a cooler’s pad before storage, rather than waiting until it’s brought back out next season, means it’s ready to use immediately rather than needing attention before the first hot day.
A breathable cover beats a sealed bag
A fitted, breathable cover keeps dust out without trapping condensation the way a fully sealed plastic bag can on a unit put away slightly damp. If using a generic cover rather than one sized for the appliance, check it isn’t so tight it restricts air around the unit entirely.
What we would not do
Store a fan or cooler in a garage or shed with no protection at all, assuming it survived fine last year. Dust accumulation and pest access both compound year over year — a basic cover is cheap insurance against a problem that’s harder to fix once it’s inside the motor.
The questions that keep coming up
Should I empty an evaporative cooler's tank before storing it?
Yes, completely — standing water left in a tank for months is exactly the kind of stagnant, warm environment that breeds mold and odor. Empty, rinse, and let it dry fully before boxing it away.
Is it fine to cover an appliance while it's still slightly damp?
No — a cover trapping residual moisture against a motor housing is a more common cause of off-season corrosion than dust ever is. Let any appliance run dry for a few hours before covering it for storage.
Last reviewed 24 August 2026
