Why Does My Garage Get Hot in the Summer?


Who doesn’t love summer? Your garage, that’s who. If it seems like your garage is twenty degrees hotter than the outdoors (which is already hot enough), then you’re probably right. It’s no mystery why this is, so let’s look at the reasons your garage gets hot and then we can explore solutions for keeping it cool.

Why is it hot?

There are plenty of factors that can lead to your garage becoming a sauna. Some of these are within your control while others aren’t. First, the sun. No one can stop the sun from beating down with all it’s might directly into your garage. West facing garages will receive the most sunlight during the mid and late afternoon, the hottest part of the day. Darker colored garage doors and house colors can also soak up heat which leaks into your garage space, raising the temperature.

If your car is so hot that you can barely touch the seatbelt, it’s a sure bet that when you park it in the garage, all the heat from the engine will radiate into the room, increasing the heat by quite a bit. Let the car cool in your driveway before parking inside for the night.

READ MORE: How to Increase the Airflow in Your Garage

Insulation and ventilation are perhaps the two biggest factors in how your garage retains heat and vents it. If you live in a cold area, you probably have an insulated garage or garage door. During summer, this can trap heat inside the space. No big deal, unless you don’t have proper ventilation. Opening garage windows (if you have them) won’t help. You need proper ventilation to really make a difference.

So, how do I keep it cool?

I’m glad you asked. The least expensive and most direct option would be fans. Box fans are inexpensive and can move a great deal of air, but you don’t want to just push the heat about the room; proper ventilation is important. Passive ventilation involves architectural elements such as turbines on the roof that connect to the garage. As hot air rises, it is pulled out the vent, keeping your garage cooler.

READ MORE: Frequently Asked Questions About Garage Doors

The other option is a mechanical system, which will need to be installed by a professional. If you spend a lot of time in your garage, a full HVAC system might be worth the time and cost of installation. Smaller window A/C units could work for smaller garages. If the heat in your garage is particular humid, you can use a standing dehumidifier. Pulling moisture from the air can keep things significantly cooler.

Other options include some garage maintenance. Make sure weatherstripping at the bottom of your garage door is sealing properly to keep out heat. Use caulk around window and doors to eliminate unwanted air flow. If you are replacing your garage door or updating the exterior of your home, choose light colors that won’t attract as much sunlight. Different garage door materials and the choice to insulate the garage door may also contribute to temperature control.

Even something as simple as organizing can make a difference. Piles of boxes on the floor can block natural air flow and ventilation, keeping the room hot and the air stagnant. Insulation is ok to invest in, but it’s really meant for the cold to keep heat in. If you want to use insulation to solve a hot garage, combine it with extra ventilation or an A/C unit for maximum efficiency.