If you're not cognizant of what's going on you can cause mold issues by carelessly using swamp coolers without any venting of the humidified air. Some people b

If you're not cognizant of what's going on you can cause mold issues by carelessly using swamp coolers without any venting of the humidified air. Some people button their place up thinking they want to keep the hot air out, but the evaporative cooler becomes ineffective once the air is too humid, and you start getting sticky. Do that enough year after year and you'll get mold in the walls.