A properly functioning swamp cooler should not make your home or belongings wet. However, evaporative coolers do add humidity to the air, which can feel different from air conditioning. Here's what to expect and when to be concerned.
Normal operation:
Evaporative coolers add moisture to the air—that's how they work. In dry climates, this added humidity is typically beneficial and comfortable. You should notice:
- Air feels less dry than outside
- Indoor humidity around 30-50% (still comfortable)
- No condensation on surfaces
- No dampness on floors or furniture
When wetness IS a problem:
If you're experiencing actual wetness, something is wrong:
1. Water leaks from the unit
- Cause: Overflow, cracked pan, loose connections
- Solution: Check float valve, inspect for cracks, tighten fittings
2. Dripping from ductwork
- Cause: Condensation from temperature differential, or water carrying through ducts
- Solution: Insulate ducts, check for excess water at pads
3. Wet spots on ceiling/wall near cooler
- Cause: Roof leak around unit, condensation
- Solution: Check roof seal, ensure proper installation
4. Humid/clammy feeling indoors
- Cause: Inadequate ventilation, running when outdoor humidity is high
- Solution: Open more windows, stop using cooler when humidity exceeds 50%
5. Condensation on windows
- Cause: Indoor humidity too high, poor ventilation
- Solution: Increase ventilation, reduce cooler usage
Ventilation is key:
The main reason homes feel too humid with a swamp cooler is inadequate exhaust ventilation. The moist air must have somewhere to go. If windows aren't open:
- Humidity accumulates
- Cooling effectiveness drops
- Air feels sticky rather than cool
Floor shouldn't get wet:
If your floor is wet near the cooler, check for:
- Water overflow from the reservoir
- Leaking pump or connections
- Condensation dripping from supply ducts
- Rain water entering through the unit (roof-mounted)
Bottom line: Swamp coolers make air more humid, not wet. If anything in your home is actually getting wet, there's a malfunction that needs attention.