Hansberger Refrigeration Blog: Your AC Repair Resource

How to Check for Air Leaks Around the House

How to Check for Air Leaks Around the HouseYou wouldn’t leave a window or front door wide open on a cold winter’s night or a hot summer’s day. In essence, big and small air leaks in your home’s envelope do the same thing — allow conditioned air to escape your living spaces. If your home wasn’t as comfortable as you would like this winter season, use these tips to detect and seal leaks heading into spring.

Home Exterior

Seal exterior air leaks less than one-half-inch wide with caulk. Use a can of spray foam for larger gaps. Check the following:

  • Seal pipe, cable, vent and wiring wall penetrations.
  • Seal cracks and holes at the foundation and walls.
  • Seal cracks and holes where two different wall materials meet.


If you are going to seal leaks in your attic, be very careful. In fact, consider hiring a professional.

  • Use spray foam or fiberglass insulation to plug gaps in stud cavities.
  • Check all piping, recessed lighting, flues and other penetrations for gaps that need to be sealed.
  • Seal the attic hatch with foam weatherstripping.


Air sealing your basement helps reduce cold floors and drafts from beneath. Here’s what to do:

  • Seal the openings from electrical, gas and water lines.
  • Seal cracks and holes in the walls and floor.
  • If you have ducts in the basement (or attic), seal loose joints with metal tape.

Windows, Doors and Interior Walls

At this point, the most difficult work is finished. Now, you can relax in the comfort of the living spaces and hunt down those leaks around windows, doors, walls, dryer vent and plumbing pipes. Here’s what to do:

The smoke test for leaks involves using a lit incense stick, holding near common leak spots and seeing if the smoke shifts side to side. When the smoke does move from its normal drift, you have found an air leak.

Use the same caulk and spray foam to seal most leaks. Rope caulk is helpful to stop leaks at windowsills, since the caulk may be removed.

For a professionals touch detecting and sealing air leaks, please contact us at Hansberger Refrigeration and Electric Company.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about air leaks and other HVAC topics, download our free Home Comfort Guide or call us at 928-723-3183.