Topic
Climate and Humidity
An evaporative cooler is only as good as the dry air feeding it. Learn how to read your local climate, what happens during humid spells, and how the added moisture affects your home.
Start here
Do Swamp Coolers Work in Humidity? Where the Cutoff Really IsSwamp coolers lose effectiveness as humidity rises because damp air cannot absorb much more water. They work well when the outdoor wet bulb is below about 70 F, poorly above about 75 F. On a 95 F day that means roughly under 30% relative humidity works well, while 40% or more gives warm, sticky results.
Original data
Swamp Cooler Climate Index: How Well Evaporative Cooling Works in 50 U.S. CitiesCalculated swamp cooler supply air temperatures for 50 U.S. cities on a hot design day, with aspen and rigid media, rated excellent to poor.
All climate and humidity guides
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