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

The absolute centimeter-gram-second unit of force; that force that will impart to a free mass of one gram an acceleration of one centimeter per second per second.

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

The energy developed through the use of heat energy.

The trapping of light inside a semiconductor material by refracting and reflecting the light at critical angles; trapped light will travel further in the material, greatly increasing the probability of absorption and hence of producing charge carriers.

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 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.

Any coefficient used to calculate heat transmission by conduction, convection, or radiation through materials or structures.

The quantity of heat produced to change a unit weight of a liquid to vapor with no change in temperature.

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

The amount of solar radiation striking a surface per unit of time and area.

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

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.

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

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 ...

The arithmetic wind speed over a specified time period and height above the ground (the majority of U.S. National Weather Service anemometers are at 20 feet (6.1 meters).

To exceed the design capacity of a device.

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 ...

The flow of heat from one area to another by conduction, convection, and/or radiation. Heat flows naturally from a warmer to a cooler material or space.

A statement of the electric rate(s), terms, and conditions for electricity sale or supply.