A heating system that uses only outside air for combustion and vents combustion gases directly to the outdoors. These systems are less likely to backdraft and to negatively affect indoor air quality.

All the components of the appliance used to condition interior air of a building.

A type of water heater that has no storage tank thus eliminating storage tank standby losses. Cold water travels through a pipe into the unit, and either a gas burner or an electric element heats the water only when needed.

A heat exchanger for recovering heat from flue gases for heating water or air.

A wood-burning appliance for space and/or water heating and/or cooking.

The amount (percent) of light that is reflected by a surface relative to the amount that strikes it.

The process of characterizing the wind resource, and its energy potential, for a specific site or geographical area.

One thousand kilowatts, or 1 million watts; standard measure of electric power plant generating capacity.

A gas or liquid used to move heat energy from one place to another; a refrigerant.

Alternating current in which three separate pulses are present, identical in frequency and voltage, but separated 120 degrees in phase.

The ratio of the minimum amount of work or energy required to perform a task to the amount actually used.

Those privately or publicly owned establishments that generate, transmit, distribute, or sell electricity.

A mathematical representation of the frequency or ratio that specific wind speeds occur within a specified time interval.

A building design that uses structural elements of a building to heat and cool a building, without the use of mechanical equipment, which requires careful consideration of the local climate and solar energy resource, building orientation, and landscape fe ...

The difference between the total cooling effect and the dehumidifying effect.

The products of all combustion processes formed by the combination of nitrogen and oxygen.

A popular term used to describe the increase in average global temperatures due to the greenhouse effect.

In a given electrical circuit, the amount of current in amperes (i) is equal to the pressure in volts (V) divided by the resistance, in ohms (R).

A measure of the average amount of a specified pollutant or material emitted for a specific type of fuel or process.

A building energy auditing technique for locating areas of low insulation in a building envelope by means of a thermographic scanner.