Monday, August 15, 2016
I've found people have often said that you want a fan to be blowing down on you in order to keep you cool. Well, this isn't always the case. If it's cooler outside than inside, having the fan blow upward toward the ceiling will cause air and heat to flow out through the roof (via fissures in the ceiling and thermodynamics). It's not as good as having a fan blow up into the attic, which is doable, I've seen it, but if you're a renter, or are just starting out, having the fan blow up will cause a vacuum which will cause air to flow in from the outside.
I wouldn't recommend this though if it is already cooler inside than outside, in that case, having the fan blow down on you will feel better, temporarily, but you may want to switch the fan at night to blow up, to pull cooler air in, if you need it.
Peace, hope, and love to you.