The pressure of the steam or water in a boiler as measured; usually expressed in pounds per square inch gauge (psig).

The angular position of the sun at solar noon with respect to the plane of the equator.

The wind speed and direction in an undisturbed flow.

A naturally occurring radioactive gas found in the U.S. in nearly all types of soil, rock, and water. It can migrate into most buildings. Studies have linked high concentrations of radon to lung cancer.

The relationship of a building to true south, as specified by the direction of its longest axis.

A heat exchanger coil in which a fluid such as water is circulated and a fan blows air over the coil to distribute heat or cool air to the different rooms.

The process of moving air (changing) into and out of an interior space either by natural or mechanically induced (forced) means.

The maximum possible voltage across a photovoltaic cell; the voltage across the cell in sunlight when no current is flowing.

A device used to simulate the angle of the sun for assessing shading potentials of building structures or landscape features.

The pressure corresponding to the outlet velocity of a fan; the kinetic energy per unit volume of flowing air.

A type of insulation material with fine, closed cells, containing a mixture of air and refrigerant gas. This insulation has a high R-value, good moisture resistance, and high structural strength compared to other rigid insulation materials.

A facility or piece of equipment that produces electricity.

A type of vertical-axis wind machine that has long, thin blades in the shape of loops connected to the top and bottom of the axle; often called an "eggbeater windmill."

The amount of heat energy that may be converted into useful energy from a fuel.

A two step process where in the first step natural gas is exposed to a high-temperature steam to produce hydrogen, carbon monoxide, and carbon dioxide. The second step is to convert the carbon monoxide with steam to produce additional hydrogen and carbon ...

The amount of BTU's/hour or kW's produced by a heating system from the burning of a fuel.

The housing around a motor that supports the active parts and protects them. They come in different varieties (open, protected) depending on the degree of protection required.

A holding pond for livestock manure that is designed to anaerobically stabilize manure, and may be designed to capture biogas, with the use of an impermeable, floating cover.

A type of (geothermal) heat pump that uses well (ground) or surface water as a heat source. Water has a more stable seasonal temperature than air thus making for a more efficient heat source.

A group of organic compounds composed of carbon, hydrogen, and oxygen; a series of molecules composed of a hydrocarbon plus a hydroxyl group; includes methanol, ethanol, isopropyl alcohol and others.