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You might be surprised to learn how much heat your home is loosing through the windows. According to

Important! Do these tests on a windy day. Days with still air can give you incorrect results.

The Candle Test

The candle test is an easy and reliable way to test for window drafts. It’s also the best method for pinpointing the leak. Use caution while conducting this test, and move any flammable materials like curtains out of the way. Be sure to conduct this test on a windy day for best results.

  1. Prepare your test area & gather materials. You will need a candle, matches, a stool, and note taking material. Be sure to choose a candle that’s easy to carry.
  2. Turn off all fans and close doors to ensure the air indoors is as still as possible.
  3. Light your candle.
  4. Hold the candle as still as possible near the seams of the window. Tip: You may want to use a small table or the window sill to help you keep the candle still.
  5. Watch the flame for signs of air movement coming from the direction of the window. A window draft will likely push or pull the flame in one direction.
  6. Study the results: If the flame remains straight then the window is likely well sealed. If the flame is bent or curved, then you likely have a window draft. The more the flame is curved and moving, then the bigger the draft.
  7. Test different areas of the window seems from top to bottom, and don’t forget the center if you have a seem there. Your window could be well sealed in one place, but leaky in another.
  8. Keep track of the results by writing down which window you tested and where you saw the draft. You can also make a light pencil mark or place a piece of masking tape on the window frame itself if you want to pinpoint the leak.

The Curtain Test

Another great way to test for drafts is by using some light curtains or fabric. If you already have those hung, then your in luck! Make sure the curtains are super lightweight and fairly tightly woven, so they will easily catch air movement. Light shower curtains can also do the trick. Remember, for best results, do this test on a windy day.

  1. Gather your materials: a lightweight curtain and note taking material.
  2. Hang the curtains in front of the window. Tip: If you want something temporary and portable, try hanging some on a rolling wardrobe rack.
  3. Close all the windows, turn off fans, and close doors to keep the inside air still.
  4. Watch and wait to see if there is movement in the curtain.
  5. Study the results: If the curtains are sucked inward or pushed out by the window, then you have a draft. If they remain still, then you likely have pretty well sealed windows.
  6. Keep track by jotting down the results. Rate the severity of the movement to note where the worst drafts are.

Now you know where the drafts are!

From here you can decide whether to try fixing the leaks or replacing the windows completely. If you did not locate any drafts, but you still feel the windows are inefficient, then you might be right. Single pane windows can be very inefficient even if they are properly sealed with no major drafts. There certainly could be other sources of heat loss.

Check out these 5 quick fixes for drafty windows…

If you’re ready to replace those drafty windows, then contact us! Opal Enterprises offers energy efficient window replacement in Naperville and throughout the west & southwestern suburbs. Learn more about our window replacement services here:

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