Choose a cold and windy day and go exploring for leaks in the house. Use a candle, a smoke-producing item (incense stick or other) or ultra-light items such as a feather, a piece of cloth or plastic wrap attached to a stick. This will allow you to walk around the house and the object will react if air gets in its way. In the case of a flame, it will oscillate.
Tip: To accentuate air infiltrations and help you locate them, turn on all air extractors such as bathroom fans, dryer, kitchen hood, central vacuum… This will depressurize the house and increase the infiltrations which will become easier to find.
Another tip: To check the airtightness of weatherstripping, also known as weather stripping, wait until darkness falls. Turn off all interior and exterior lights first. From inside the house, sweep the contours of doors and windows with a powerful light source. The light will come out as soon as there is even the slightest vanishing point. Ideally, make sure there are two, one person lighting and the other observing.
Once found, be sure to make the appropriate repairs or have your windows professionally installed. At Solution Thermo, we make it our business.