ealant on larger gaps around windows, baseboards, and other places where air may leak out. ??? Cover your kitchen exhaust fan to stop air leaks when not in use. ??? Replace door bottoms and thresholds with ones that have pliable sealing gaskets. ??? Keep the fireplace flue damper tightly closed when not in use. ??? Seal air leaks around fireplace chimneys, furnaces, and gas-fired water heater vent