The space within a building or structure that is normally occupied by people, and that may be conditioned (heated, cooled and/or ventilated).

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

The amount of energy derived from an electrical source per unit quantity of electricity passing through the source.2. Electrical potential; voltage.

The energy developed through the use of heat energy.

The distance between similar points on successive waves.

The period of low energy demand, as opposed to maximum, or peak, demand.

A type of heat pump that uses the ground, ground water, or ponds as a heat source and heat sink, rather than outside air. Ground or water temperatures are more constant and are warmer in winter and cooler in summer than air temperatures. Geothermal heat p ...

A way of joining photovoltaic cells by connecting positive leads to negative leads; such a configuration increases the voltage.

The standard method for calculating residential cooling loads developed by the Air-Conditioning and Refrigeration Institute (ARI) and the Air Conditioning Contractors of America (ACCA) based largely on the American Society of Heating, Refrigeration, and A ...

A device used to control temperatures; used to control the operation of heating and cooling devices by turning the device on or off when a specified temperature is reached.

A unit of rate of operation. Electrical Hp: a measure of time rate of mechanical energy output; usually applied to electric motors as the maximum output; 1 electrical Hp is equal to 0.746 kilowatts or 2,545 Btu per hour. Shaft Hp: a measure of the actual ...

The force that pulls a wind turbine blade, as opposed to drag.

A type of heating system where heat, resulting when electric current flows through an "element" or conductor, such as Nichrome, which has a high resistance, is radiated to a room.

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

The amount of heat produced from the complete combustion of a unit of fuel. The higher (or gross) heating value is that when all products of combustion are cooled to the pre-combustion temperature, water vapor formed during combustion is condensed, and ne ...

A water heater that heats water before it is directly distributed for end use as required; a demand water heater.

A form of thermal energy resulting from combustion, chemical reaction, friction, or movement of electricity. As a thermodynamic condition, heat, at a constant pressure, is equal to internal or intrinsic energy plus pressure times volume.

A device consisting of two dissimilar conductors with their ends connected together. When the two junctions are at different temperatures, a small voltage is generated.

Energy supplied during periods of relatively high system demands as specified by the supplier.

The processes that a work input/output system undergoes and in which the initial and final states are identical.