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

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

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

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

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

A device that converts heat or sunlight directly to electricity, invented by Standford Ovshinsky, that has a unique glass composition that changes from an electrically non-conducting state to a semiconducting state.

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."

A term used for a wind energy conversion device that produces electricity; typically having one, two, or three blades.

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 ...

Ratio of useful energy output of a device to the energy input, averaged over an entire heating season.

A facility or piece of equipment that produces electricity.

The interior heat gain due to heat conduction, convection, and radiation from the exterior into the interior, and from occupants and appliances.

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 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.

Houses that have earth berms around exterior walls.

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 type of heat pump that uses sealed horizontal or vertical pipes, buried in the ground, as heat exchangers through which a fluid is circulated to transfer heat.

The wind speed and direction in an undisturbed flow.

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.

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