The device in an air conditioner or heat pump in which the refrigerant condenses from a gas to a liquid when it is depressurized or cooled.

The ratio of average energy demand (load) to maximum demand (peak load) during a specific period.

A type of structural, insulated product with foam insulation contained between two facings of drywall, or structural wood composition boards such as plywood, waferboard, and oriented strand board.

The value or purchasing power of a dollar in a specified year carried forward or backward.

A popular term for localized or on-site power generation.

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

The fossil fuels: coal, oil, and natural gas.

A measure of light quality. The maximum CRI value of 100 is given to natural daylight and incandescent lighting. The closer a lamp's CRI rating is to 100, the better its ability to show true colors to the human eye.

A term used to describe solar thermal, central receiver, power systems, where an array of reflectors focus sunlight onto a central receiver and absorber mounted on a tower.

Low or medium Btu content gas, composed mainly of carbon monoxide, nitrogen(2), and hydrogen(2) made by the gasification of wood or coal.

The amount of work done in raising one pound one foot.

A solar heating system that uses a liquid as the heat transfer fluid.

The lower or net heat of combustion for a fuel that assumes that all products of combustion are in a gaseous state. (See Net Heating Value below.)

A unit of volume equal to 1 cubic foot at a pressure base of 14.73 pounds standard per square inch absolute and a temperature base of 60 degrees Fahrenheit.

The process of controlling indoor moisture levels and condensation.

The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm).

A type of anaerobic digester that has a horizontal tank in which a constant volume of material is added and forces material in the tank to move through the tank and be digested.

A unit of pressure [hydraulic (liquid) or pneumatic (gas)] that does not include atmospheric pressure.

The ability of an electric power consumer to purchase electricity from a supplier of their choice without being physically inhibited by the owner of the electric distribution and transmission system to which the consumer is connected to. (See also Open Ac ...

A type of insulation that is molded or expanded to produce coarse, closed cells containing air. The rigid cellular structure provides thermal and acoustical insulation, strength with low weight, and coverage with few heat loss paths. Often used to insulat ...