3 Places to Test Your Home for Drafts and Leaks

Insulation, an energy-efficient air conditioning system, and using a ceiling fan to cut cooling costs will still lack the desired effect on your cooling costs this coming summer if your home is still leaking. Leaks in walls, window sills, and doors are all easy escape routes for cold air to swap space with the warm air outside. According to the laws of thermodynamic, heat will always move from a place of higher energy to a lower energy space (hot to cold), robbing you of the comfort your home should otherwise have. Before that first heat wave hits, take the time to double-check your home for potential leaks and drafts.

Window Sill Leaks are a common place to find a sudden leak. Over time, the sunlight erodes the synthetic sealing of weather strips around your window sills. The chill of winter followed by the warming of spring and that first chance to open a window can cause the stripping around a sill to crack or break. Make a visual inspection of the sill and look for damaged wood, weather stripping, or cracked glass around the edges.

Door Jamb Leaks are probably more common than window leaks. Foundation damage from a warm winter, excessive rains, or the recent drought can lead to doors that no longer fit well and create gaps. Storm door weather stripping and sweeps (the brush on the base of the door) can also be damaged over time and should be replaced if you find holes, cracks, or missing segments.

Exterior Damage is another source of leaks and drafts. It’s a good idea, especially after a storm, to examine your home from the outside. Walk around the full exterior of your home and look for damage to vents, exhausts, siding, and the roof. If there’s a dent, missing shingle, or crack, you may find a hole as well.

Testing for Drafts

There’s one other method you can test for leaks in your home: a smoke test.

  1. Close all exterior windows and doors in the home, leaving internal doors open.
  2. Shut off the central air and any ceiling fans.
  3. Light an incense stick and watch the smoke. If it moves sideways, it’s following an air current in the room.
  4. Follow the smoke trail and see if it leads to a gap or an exit.
  5. Use this method around windows, doors, and vents to find tiny gaps and leaks.

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