Hi Albert, swamp coolers do not work well if the dew point is about about 34°. So what we do at our house is go to Weather Underground for our zip code and it shows the dew point. Above about 32° we turn on the a/c. If the swamper is on and cooling nicely, we just leave it on 24/7 unless we get too cold. Hope this helps.

Usually just turn it off when you're cold. Or if the humidity is so high that you can't stand having it on.

The real tip I can give you is to either get your float right so the unit isn't belching water all over your roof or to install it so it overhangs your yard & runs away from the house. Do not ever ever let the thing leak onto the structure of your home. Ever. It will not hurt it for a day or two but in the long run, you will cause thousands and thousands of dollars in structural damage to your home. Trust me. It will absolutely ruin your roof if it leaks up there or corrode your foundation if you have it dump at the stem wall.

Ours runs off into my garden via a hose from the roof unit.