Photo: Jason Finn (Shutterstock)
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.
Cool a room by turning off ... everything
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:
Turn off lights. Old-school incandescent light bulbs generate a lot of heat. Keeping them off will lower the overall temperature. Switching to cooler LED or CFL light bulbs will also help. Turn off appliances. Even when not in active use, many appliances generate heat. If your windowless room serves as the laundry room or has a computer, refrigerator, or other appliance in it, think about whether those appliances can be relocated or if they need to be on all the time.Air conditioner options
Most air conditioners are designed to use outside air and drainage, but you do have a few options for a windowless room:
In-wall AC. If you’re reasonably handy and the room in question has an exterior wall, consider installing a through-the-wall AC. This will give you a standard air conditioning experience, no window required. Ventless ACs (aka “swamp coolers”). These might be called air conditioners, but they’re actually evaporative coolers. They work by evaporating a supply of water inside them, which actually does work to cool down a room as long as the climate is dry—in humid conditions the water can’t evaporate as effectively. You can even DIY a swamp cooler pretty easily if you can’t afford to buy one. Even hanging a wet towel in front of a fan will help! Portable AC with extended drainage. Portable air conditioners work just like window units, but are designed to sit on the floor with a flexible vent that can fit into a window. That vent can be extended, so if there’s a window near the room but not in the room, you can extend its reach by buying some hose and attaching it via duct tape. There is one caveat, however: The blower fan in your AC unit might not have enough power to push the exhaust as far as you want it, so extending the exhaust tube might reduce its effectiveness.Beat the heat with a fan (or fans)
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:
Ceiling fans. Installing a ceiling fan might require some wiring work, but it’ll be worth it. Setting the fan to pull air up from below will circulate cooler air through the room, lowering the overall temperature. And the movement of the air will also help you feel cooler in the space. Standing fans. If the windowless room doesn’t have a ceiling fan, two standing fans can help. Aim one fan up toward the ceiling, and the other out of the room through the doorway. This will vent hot air that’s rising to the ceiling out into the rest of the house, helping to cool down the space. Exhaust fan. If your windowless wonder has an en-suite bathroom with an exhaust fan, leave the bathroom door open and run the exhaust fan. It will draw some of the hot air up and out. Exhaust fans tend to be on the smaller side, so this likely won’t solve your problem entirely—but it will help a little. Ice fan. Yep, a bucket of ice placed in front of a fan will help cool down a space. This is very similar to the DIY swamp cooler concept, but it’s a little less involved and easier to throw together if you’re desperate.Use paint to lower the temperature
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.
