A term used for lighting appliances; the ratio of lumens received on a flat surface to the light output, in lumens, from a lamp; used to evaluate the effectiveness of luminaries in delivering light.

A device for removing heat from a gas or liquid stream for air conditioning/cooling.

A federal government agency involved in rural development, marketing and regulatory programs, food safety, research, education and economics, food, nutrition and consumer service, farm and foreign agricultural services, and natural resources and environme ...

A type of insulation made from virgin basalt, an igneous rock, and spun into loose fill or a batt. It is fire resistant and helps with soundproofing.

A popular term used for a length of wood or steel used in or for wall framing.

A process for making inexpensive Galium Arsenide (GaAs)photovoltaic cells in which a thin film of GaAs is grown atop a thick, single-crystal GaAs (or other suitable material) substrate and then is cleaved from the substrate and incorporated into a cell, a ...

A window located high in a wall near the eaves that allows daylight into a building interior, and may be used for ventilation and solar heat gain.

Defects, such as dangling bonds, induced in an amorphous silicon semiconductor upon initial exposure to light.

A company that specializes in undertaking energy efficiency measures under a contractual arrangement whereby the ESCo shares the value of energy savings with their customer.

The sum of the sensible and latent heat in a substance or fluid above a base point, usually 32 degrees Fahrenheit.

An electric motor rated at less than one horse power (hp).

The smallest self-contained, environmentally protected structure housing interconnected photovoltaic cells and providing a single dc electrical output; also called a panel.

The energy liberated in a chemical reaction, as in the combustion of fuels.

An apparatus for measuring force or power, especially the power developed by a motor.

A slab floor that sits directly on top of the surrounding ground.

A device used to compress air for mechanical or electrical power production, and in air conditioners, heat pumps, and refrigerators to pressurize the refrigerant and enabling it to flow through the system.

A liquid byproduct of wood combustion (or distillation) that condenses on the internal surfaces of vents and chimneys, which if not removed regularly, can corrode the surfaces and fuel a chimney fire.

A type of furnace or reactor in which the emission of sulfur compounds is lowered by the addition of crushed limestone in the fluidized bed thus obviating the need for much of the expensive stack gas clean-up equipment. The particles are collected and rec ...

A free and mobile conduction electron or hole in a semiconductor.

A fluorescent lamp that has a tubular shape.