How to Cool Off a Windowless Room

If you live in a home with a windowless room inside it, you know how hot it can get. A room without windows is typically a room without ventilation, and unless you have a robust air conditioning system that blasts cold air into that small slice of Mordor you call your unofficial spare bedroom, it’s almost certainly a stuffy, uncomfortable hellhole. If you don’t have the scratch to install central air conditioning or a mini-split system, however, you’re not doomed to Death by Sweat in that cell-like space. Here are all the ways you can cool off a windowless room.

Your first step in cooling down the room is to manage the environment inside it. The heat making your life miserable is often (partially) coming from inside the house, after all, so do these things first:

Most air conditioners are designed to use outside air and drainage, but you do have a few options for a windowless room:

If an air conditioner or swamp cooler isn’t in the cards, you can turn to old-school fan technology to cool down a room. It’s all about air circulation:

Finally, if your windowless room has exterior walls or an exposed roof line, consider slapping some heat-reflective paint on the walls and roof. It’s pretty well-known that painting your house a lighter color helps cool it down, so painting the walls and roof surrounding your room a bright white will help cool it down.

You can also consider using a heat-reflective paint that’s formulated to reflect light and heat, keeping the exterior temperature of your walls and roof low, which in turn means less heat transfer to the interior. These paints are typically a bit more complex to apply than regular paint, so you might need to hire a professional for this, but it could give you an edge in keeping that windowless room cool.