ENERGY STAR — ENERGY STAR is a government-backed program helping businesses and individuals protect the environment through superior energy efficiency.

ENERGY STAR Home Sealing — A process recommended by the ENERGY STAR Program for improving the envelope of a home to make it more comfortable and energy-efficient. The process includes sealing air leaks and adding insulation where cost-effective.

Air Duct — A hollow conduit or tube (square or round) that circulates air from a forced-air heating and/or cooling system to a room (supply duct) or returns air back to the main system from a room (return duct).

Air Leak — A hole, crack, or gap where air can leak in or out of a house. Air leaks can make a home feel drafty or uncomfortable and waste energy.

Gable Vent — A screened vent installed at or near the peak of a roof gable that allows warm attic air to escape.

Insulation — A material that is designed to slow down the flow of heat in or out of a building structure.

Joist — A beam used to support floors or roofs.

Kneewall — A short wall in a room with a sloped ceiling. It is usually formed when the room ceiling follows the roof line of a house.

Rafter Vent — A vent leading from the soffit into the attic through the space between the attic rafters. This vent allows air to correctly flow past insulation into the attic space.

Recessed "Can" Light — A metal light fi xture (or can) that is inset into the ceiling. These fixtures can be a big source of air leaks when installed in the upper fl oor of a home.

Ridge Vent — A screened vent installed along the top ridge of a roof that allows warm attic air to escape.

Sill Plate — A wood plank that lays flat on top of a concrete or masonry foundation or wall that supports a floor or ceiling joist.

Soffit — The underside of a building overhang, beam, or arch, especially the underside of a stair or roof overhang.

Soffit Vent — A screened vent in a house soffit that allows air to flow into the attic or the space below the roof sheathing. This helps keep the attic cool in the summer and allows moisture in the attic to evaporate.