2. Thermal Leak Detector
A full home energy audit might be the best way to find air leaks. But a quick-and-dirty DIY substitute is to use a thermal-leak detector. It uses infrared sensors to measure temperatures, so you can wave it across your walls, windows, and ceilings to instantly identify hot and cold spots that would indicate a draft. The Black & Decker version, which is one of the lowest-priced detectors we found, costs $28. It gives you the temperature on a monitor and also has a light that changes to red for warm spots, and blue for cool ones.
