The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.

see Solar Spectrum above.

A popular term for energy produced from renewable energy resources.

The conversion of electric power to visible light by using an electric charge to excite gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produc ...

A heat exchanger in which two fluids flow in opposite directions for transfer heat energy from one to the other.

A type of solar thermal system where sunlight is concentrated by a curved reflector onto a pipe containing a working fluid that can be used for process heat or to produce electricity. The world's largest solar thermal electric power plants use solar troug ...

A fuel gas with a heating value between 90 and 200 Btu per cubic foot.

A method used to estimate building heating loads by assuming that heat loss and gain is proportional to the equivalent heat-loss coefficient for the building envelope.

The potentially useful byproducts of ethanol fermentation process.

Those gases, such as water vapor, carbon dioxide, tropospheric ozone, methane, and low level ozone that are transparent to solar radiation, but opaque to long wave radiation, and which contribute to the greenhouse effect.

Materials with high thermal energy storage capacity contained in or part of a building's walls, floors, or freestanding elements.

The quantity of heat that a cooling appliance is capable of removing from a room in one hour.

A solid that contains pores; normally, it refers to interconnected pores that can transmit the flow of fluids. (The term refers to the aquifer geology when discussing sites for CAES.)

Water in vapor form; used as the working fluid in steam turbines and heating systems.

Salt mixtures with potential applications as solar thermal energy storage materials.

The interior area of a building, calculated in square feet or meters.

A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.

The air that is supplied to the combustion chamber of a furnace.

Thermal energy that is used in agricultural and industrial operations.

A type of high intensity discharge light that has the most lumens per watt of any light source.