A building element that provides protection against the sun, wind, and precipitation.

This type of heat pump is known as an air-to air system.

The amount of conditioned air to be supplied by a cooling system; usually the maximum amount to be delivered based on a specified number of cooling degree days or design temperature.

A power plant that uses two thermodynamic cycles to achieve higher overall system efficiency; e.g.: the heat from a gas-fired combustion turbine is used to generate steam for heating or to operate a steam turbine to generate additional electricity.

A utility owned by stockholders or other investors; sometimes referred to as a private utility, in contrast to a public utility that is owned by a government agency or cooperative.

An unregulated subsidiary of an electric utility that is allowed to generate and sell wholesale power as an independent energy producer, and is exempt from the Public Utility Holding Company Act of 1935.

The direct, diffuse, and reflected solar radiation that strikes a surface.

In reference to solar photovoltaic devices, the growth of one crystal on the surface of another crystal. The growth of the deposited crystal is oriented by the lattice structure of the original crystal.

A device that that converts direct current electricity (from for example a solar photovoltaic module or array) to alternating current for use directly to operate appliances or to supply power to a electricity grid.

A frequently used room or area that is maintained at a more comfortable level than the rest of the house; also known as a "warm room."

A solar collector in which the absorber is contained in a sealed glass tube, thereby providing for relatively high temperature heat gain.

A particle of light that acts as an individual unit of energy.

A cooling device that uses mechanical energy to produce chilled water.

A nationally recognized energy rating program that gives builders, mortgage lenders, secondary lending markets, homeowners, sellers, and buyers a precise evaluation of energy losing deficiency's in homes. Builders can use this system to gauge the energy q ...

A measure of the moisture content of air; may be expressed as absolute, mixing ratio, saturation deficit, relative, or specific.

A device or material with a high resistance to electricity flow.

A concrete pad that sits on gravel or crushed rock, well-compacted soil either level with the ground or above the ground.

A load management objective that moves loads from on-peak periods to off-peak periods.

The highest wind speed at which a wind turbine stops producing power.

A type of combustion heating system in which combustion air is drawn directly from outside and the products of combustion are vented directly outside. These features are beneficial in tight, energy-efficient homes because they will not depressurize a home ...