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How To Find Air Leaks in Your House

Even if your house doesn't seem drafty, cracks and openings can leak out 40% of its heat. Identify them and start saving a bundle on your energy bill.


  • TIP: On a windy day, drafts can be even more obvious.
  • Step 1: Check around windows, doorframes, electrical outlets, vents, mail slots, mounted air conditioners, and places where pipes and wires come through the walls.
  • Step 2: Look outside the house too. Inspect places where the siding meets the chimney and walls meet the foundation—as well as doors, windows, corners, and any other junctions of building materials.
  • Step 3: List all the problem spots in a notebook so you can plug them up later—and start being cozier for a lot less money!
  • FACT: Many utility companies will conduct a free home energy audit to help you save energy and money.
  • TIP: Along with the detector, you can use a smoking incense stick or a damp finger to test for drafts.
  • Step 4: Check for air leaks by holding the detector about one inch from all the joints in your house, and watch to see if it moves.
  • TIP: Blow lightly on the draft detector and notice how little air it takes to make the toilet paper flutter.
  • Step 5: Use scissors to cut the hanging end of the toilet paper flag into a fringe of about six 2" strips.
  • Step 6: Create a vacuum in your house by closing all doors, windows, and fireplace flues. Leave one window open and place a box fan in it, blowing out of the house.
  • Step 7: Turn off all combustible appliances such as gas furnaces and water heaters.
  • Step 8: Turn on all exhaust fans in the kitchen and bathrooms. Sucking air out of the house will force outdoor air to flow in through any small openings.
  • Step 9: Make a draft detector by taping a sheet of toilet paper to a pencil like a little flag.

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