We may receive a commission on purchases made from links. A window air conditioner can be a lifesaver in a heatwave, but how do you install one in a horizontal sliding window? Most window air ...

Q: I am renting a small, old home without central air conditioning. I have a window air conditioner, and the past few years I’ve awkwardly filled in the space around it with a large piece of plywood.

Why do window ACs actually need a window? On the surface, it feels unnecessary — after all, the unit is clearly designed to blow cold air from the front. Why can't you just set it on the floor like a ...