A construction element used for ceiling support.

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.

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

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

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

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.

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.

The path followed by electrons from a generation source, through an electrical system, and returning to the source.

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

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

The concept of capturing and converting the energy available in the motion of ocean waves to energy.

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

The transfer of heat through matter or space by means of electromagnetic waves.

The ability of a building construction assembly (partition, wall, floor, etc.) to resist the passage of fire. The rating is expressed in hours.

A device that removes contaminants, by mechanical filtration, from the fresh air stream before the air enters the living space. Filters can be installed as part of a heating/cooling system through which air flows for the purpose of removing particulates b ...

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

A device that releases pressure within a radiator when the pressure inside exceeds the operating limits of the vent.

A room heat delivery (or exchanger) component of a hydronic (hot water or steam) heating system; hot water or steam is delivered to it by natural convection or by a pump from a boiler.

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 ...