Cooling a Basement with No Windows (in Summer!)

If you’re stuck with a roasting hot basement, but no windows to open for ventilation – I hear you!

There’s nothing worse than not being able to use a whole area of your home, just because of the outside temperature. In this article, we’ll be aiming to do just that. I’ve covered 7 different ideas to help cool down a window-less basement – so hopefully at least 1 or 2 will help you out today.

There aren’t really a lot of HVAC options that can be used without professional installation, but I’ll start off with those, and then finish off with some cheaper and easier things to try that will actually work in any windowless room, not just in the basement.

*Please note only the first 2 options assume you own your home and you’re prepared to hire a professional.

Install a Mini-Spit System

Price Range: The cost of the equipment can range from $700 to $7,000 and the cost to install can range from $800 to $1,500.

Mini-spit system
Mini-spit system is enough to cool one room

Mini-splits are traditionally seen above-ground, but they can be installed in a lot of locations (as long as you have a way to connect to an outside unit through a small hole in the wall. They have one outside unit and then inside units that are mounted on the wall. You can have up to 4 interior units paired to the exterior unit.

If you have just one room you want to cool, a single indoor unit should be sufficient.

However, in order to pair the indoor and outdoor units your exterior wall will need to be drilled through, so you’ll probably need a professional to handle this installation.

Thankfully this is a pretty simple install using only a 1-2″ diameter tube – rather than a hole vent like a traditional or portable AC.

Install a Portable Air Conditioner

Price Range: $250 to $700

Portable Air Conditioner
Portable air conditioning can vent through a wall.

First of all, basically all air conditioners need to be vented. Even portable ones. Failing to vent an air conditioner to the outside will actually make your room hotter. It will also build up moisture in the room.

The good news is, you can vent a portable air conditioning unit through a wall. If you have an existing vent that goes to the outside, you can use that. Some people will even vent into another room, although that isn’t the best idea, as it’s not very efficient.

If you don’t have an existing vent, you’ll need to cut an above-grade hole in your exterior wall that’s big enough to fit an exhaust hose through.

Okay, so both of those options can be used to cool your basement without windows. Of course, they will work upstairs as well, it’s just the installation process will differ.

Now for some cheaper, easier options that will work in any room of the house, with or without windows.

Consider More Insulation

This might sound like backwards thinking, but insulation actually helps keep a room cooler as well as hotter. You’re essentially isolating the room from the outdoor temperature – which means it’ll stay warmer in the winter, and cooler in the summer.

If your basement is unfinished, it can be incredibly simple to throw up another layer or two of insulation to act as a barrier between you and the summer heat.

Keeping the floor of the basement uninsulated can also be a great idea. The further down into the ground we go, the more stable the temperature is. In summer, a basement floor can be quite cool – it’s at the ground surface where the heat comes from.

So consider adding insulation to the walls and basement ceiling if possible, but leaving the floor bare. This will give you access to the cooler underground temperatures, while blocking out the heat from above.

Rethink Your Lighting

It’s getting harder to find incandescent bulbs, but a lot of us still have them in our homes somewhere.

incandescent bulbs
Incandescent light bulbs create heat

If you’re trying to cool down your home, get rid of them. Or at least put them away until winter when you’re paying to heat your home.

An incandescent bulb produces light by heating a thin filament that is surrounded by gas. Yes, there are gases in that bulb too.  A 100-watt bulb will heat up to about 4,600 degrees F (2,500 C) internally. The surface temperature of the bulb will be anywhere between 150- and 250-degrees F (65 and 120 C).

And all that heat is in the room with you. Switch over to LED bulbs that don’t emit as much heat.

Install a Ceiling Fan

Airflow is your friend!

ceiling fan
Run your ceiling fans counterclockwise for summer

Ceiling fans can be run all year round, in both heating and cooling seasons. The trick is to change the rotation of the blades with each season. In the summer months, make sure blades are going counterclockwise. This will push air down towards the room.

Strategically Place Multiple Fans

Use this trick to literally push air through your space.

If you have air conditioning somewhere on the basement level, this works even better. Take one fan and put it closer to the cooler air, and the other one in the room you are trying to cool.

Make sure you are directing the cool air toward the room that needs cooling with both fans.

This will also work if you have a window in another room instead of air conditioning.

Pair Ice with Your Fan

This may create some unwanted humidity, but if you’re boiling to death in a hot room, you probably won’t care.

Make sure you stock up on ice—meaning you’ll need a freezer.

Get the biggest bowl you can find that will sit in front of the blades of a fan without blocking it. Fill the bowl with ice, making sure you allow for melted ice and place the fan beside it. Have the fan blowing toward the space you want to cool—blowing past the ice.

As cooler air forms above the bowl, the fan will blow it toward you. It’s not a perfect or long-term solution, but it’s better than nothing.

Consider Your Appliances and Electronics

Whatever you have that generates heat, consider turning it off. Obviously, isn’t always possible, but if you have anything you can turn off, you’re also cutting the heat in the room.


If you’re unfortunate to live in a basement with no windows, it is possible to cool it to some extent without drilling holes in the walls. However, if you really want to cool your basement, drilling is necessary.

However, consider some of the other tips. Using fans and removing items that generate heat.

Hopefully, I’ve provided enough info to help you keep cool. Thanks for reading!

While you’re here, why not check out the related posts below? Maybe we can answer some other questions you might have.