A mound of dirt next to exterior walls to provide wind protection and insulation.

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

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

The factor, when multiplied by the monthly degree-days, that yields the monthly space heating load.

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

A device used by energy auditors to pressurize a building to locate places of air leakage and energy loss.

A type of municipal solid waste (MSW) incineration facility in which MSW is burned with only minor presorting to remove oversize, hazardous, or explosive materials. Mass burn facilities can be large, with capacities of 3000 tons (2.7 million kg) of MSW pe ...

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 ratio of solar collector array area to actual land area.

The overall rate of heat loss from a building by means of transmission plus infiltration, expressed in Btu per hour, per degree temperature difference between the inside and outside.

Energy produced by the internal heat of the earth; geothermal heat sources include: hydrothermal convective systems; pressurized water reservoirs; hot dry rocks; manual gradients; and magma. Geothermal energy can be used directly for heating or to produce ...

The ratio of the maximum demand on an electricity generating and distribution system to the total connected load on the system; usually expressed as a percentage.

Any process that uses solar radiation to produce useful heat.

A non-crystalline semiconductor material that has no long-range order.

A method for making sheets of polycrystalline silicon in which silicon dendrites are slowly withdrawn from a melt of silicon whereupon a web of silicon forms between the dendrites and solidifies as it rises from the melt and cools.

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

A total life cycle cost divided into equal amounts.

The potential energy available in a fuel as received, taking into account the energy loss in evaporating and superheating the water in the fuel. Equal to the higher heating value minus 1050W where W is the weight of the water formed from the hydrogen in t ...

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."