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."

The amount of heated air, or heating capacity, to be supplied by a heating system; usually the maximum amount to be delivered based on a specified number of heating degree days or design outside temperature.

Any wholly or partially enclosed space in which combustion takes place.

Sunlight scattered by atmospheric particles and gases so that it arrives at the earth's surface from all directions and can not be focused.

The demand of a consumer of electricity at the time of a power supplier's peak system demand.

The highest possible pressure in a fuel-air mixture before spontaneous ignition occurs.

The heat produced by combusting a specific quantity and volume of fuel in an oxygen-bomb colorimeter under specific conditions.

A current carrier, either an electron or a hole, that is in the minority in a specific layer of a semiconductor material; the diffusion of minority carriers under the action of the cell junction voltage is the current in a photovoltaic device.

An insulation product made of a fibrous material or plastic foams, pressed or extruded into board-like forms. It provides thermal and acoustical insulation strength with low weight, and coverage with few heat loss paths.

The vacancy where an electron would normally exist in a solid; behaves like a positively charged particle.

A vehicle with an engine capable of operating on two different types of fuels.

Power plants, whose output depends on a factor(s) that cannot be controlled by the power generator because they utilize intermittent resources such as solar energy or the wind.

An energy band in a semiconductor in which electrons can move freely in a solid, producing a net transport of charge.

A type of window having two layers (panes or glazing) of glass separated by an air space. Each layer of glass and surrounding air space reradiates and traps some of the heat that passes through thereby increasing the windows resistance to heat loss (R-val ...

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

The planting, cultivation, and harvesting of a single species of crop in a specified area.

That part of an electricity bill that is based on the amount of electrical energy consumed or supplied.

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

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

Nonglossy paint with a relatively high absorptance.