General Tips When Doing Ductwork: Repair leaky ducts. Leaky ducts reduce heating efficiency. Have a contractor check your crawl space or attic for damaged, disconnected, or leaky ducts. Ducts should be repaired with mastic sealant, not duct tape. When Weatherproofing: Get rid of drafts and air leaks. Don't let air escape that you've paid to heat or cool. Caulk and weather-strip to reduce air leakage around doors and windows, baseboards, and wherever pipes, wires, and vents enter house. Don't forget the attic and basement. When Using Windows: Window coverings help with heating and cooling. To keep summer sun out, use awnings and close drapes and shades on south windows. In winter, open drapes and shades on south windows. Close all window coverings at night to retain indoor heat. When Heating Water: Turn down the temperature. Set water heater to the lowest temperature that provides you sufficient hot water. Wrap your older model water heater with a water heater blanket, especially if it is in an unheated area.