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View Full Version : Warm pool at night with steam/vapor?!?!



endeavor
05-09-2006, 01:58 PM
I have a pool that has been above 80 degrees fahrenheit during the night (mainly because I have solar heating, and because I keep my pool cover on during the day). Recently I went for a swim just after sunset and noticed that I could see what appeared to be steam or some kind of vapor moving over or coming out of my pool. Now I thought it can't be steam, because steam is usually water in the form of vapor, which would have to be at 212 degrees fahrenheit! The air temperature is probably in the 60s at night, and I have a chlorine salt generating pool. Does anyone know what I am seeing and can anyone explain this to me?

CrisL
05-09-2006, 02:34 PM
You are seeing water vapor - just like fog. The air just (within a few inches) above the pool is warm because the pool is warm. This allows for high humiditiy (warmer air holds more moisture than colder air). As the hot, moist air rises away from the pool, it cools and the water condenses and forms the fog or mist you see. You see it at night or very early in the morning because this is when the air temperature is cooler.