How to Check Your Home for Air Leaks Before Hot Weather


It’s summer in Texas, and your house is leaking cold air. That’s not the plot of this summer’s blockbuster horror film, it’s reality for many homeowners in the Spring and Greater Houston area. But no need to fear, the Morrow Mechanical team is here to help.

The experienced AC technicians on our team have put together instructions so you can check your own home for leaks and avoid horrifying utility bills this summer season.

How to Check Your Home for Air Leaks Before Hot Weather

Pressurization Test

The best way to check your home for leaks is a pressurization test.  The process may seem complicated at first glance, but by following these steps, any homeowner can check their house for leaks. This pressurization test is best completed on a cool, windy day.

  1. First, identify common sites for leaks.
  •  The spaces underneath doors are the most obvious places to look for leaks, keep this in mind during the pressurization test.
  • Kneewalls, the short walls that support the rafters of timber roofs, often let air escape.
  • In older homes, the space around doors and windows may have increased due to shifting over time, leading to air leaks.
  • Wiring holes are rarely perfectly fitted to ceilings and walls. They are often guilty of allowing air to leak out.
  • A lesser-recognized site for leaks, simply because they are hidden from view, are attic hatches.
  • The plastic trim around recessed lights is often not completely flush with the ceiling, causing leaks.
  1. Second, turn off all combustion appliances like furnaces and water heaters.
  2. Shut all doors, windows, and fireplace flues. This step is crucial in identifying leaks, so be thorough.
  3. Turn on any fan that blows air to the outside, like fans above the stove, or bathroom fans. Alternatively, use a large window fan to suck air out of your rooms.
  4. Finally, light a stick of incense and carry it to any area you think a leak might be occurring. If the smoke from the incense is sucked into a gap, that indicates a leak exists.

Flashlight Method

If you do not feel comfortable or able to conduct a pressurization test, you can attempt the flashlight method. This method is not as accurate as the pressurization test, but only requires a volunteer and a flashlight. Have the person carrying the flashlight shine it on potential sites of air leaks. The other person should place themselves on the other side of the potential leak to see if the light shines through. If light does shine through, there is likely an air leak in that location.

Check your home for air leaks, then get them fixed by Morrow Mechanical!

Now that you’ve identified the potential leaks in your home, you’re going to need a professional to seal them. Morrow Mechanical is a family owned and operated HVAC service and repair company operating in the Spring and Greater Houston area. Call us at 281-301-0560 to schedule your HVAC service, repair, or maintenance today.