Features and vegetation on the outside of or surrounding a building for aesthetics and energy conservation.

A mechanical/electrical device used to pull air out of an interior space; usually located in the highest location of a building, in the ceiling, and venting to the attic or directly to the outside.

A charge for the maximum rate at which energy is used during peak hours of a billing period. That part of a utility service charged for on the basis of the possible demand as distinguished from the energy actually consumed.

A form of thermal energy resulting from combustion, chemical reaction, friction, or movement of electricity. As a thermodynamic condition, heat, at a constant pressure, is equal to internal or intrinsic energy plus pressure times volume.

The trapping of light inside a semiconductor material by refracting and reflecting the light at critical angles; trapped light will travel further in the material, greatly increasing the probability of absorption and hence of producing charge carriers.

A solar thermal collector that has an absorber that does not have a glazed covering. Solar swimming pool heater systems usually use unglazed collectors because they circulate relatively large volumes of water through the collector and capture nearly 80 pe ...

The unit price and quantity to which it applies as specified in a rate schedule or contract.

The force that pulls a wind turbine blade, as opposed to drag.

The decomposition of organic material to alcohol, methane, etc., by organisms, such as yeast or bacteria, usually in the absence of oxygen.

The amount of useful energy produced by a system less the amount of energy required to produce the fuel.

A description of how well people in a lighted space can see to do visual tasks and how visually comfortable they feel in that space.

The sum of all the costs both recurring and nonrecurring, related to a product, structure, system, or service during its life span or specified time period.

A profile of how the wind speed changes with height above the surface of the ground or water.

A construction element used for ceiling support.

Standardized weights or volumes for heating fuels.

Fuel gas with a heating value of between 200 and 300 Btu per cubic foot.

A column of burning combustion gases that are so hot and strong that the heat is lost up the chimney before it can be transferred to the house. A draft brings air to the fire to help keep it burning.

The processes that a work input/output system undergoes and in which the initial and final states are identical.

The arrangement, proportion, and design of windows in a building.

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 ...