The structural elements (walls, roof, floor, foundation) of a building that encloses conditioned space; the building shell.

A device that captures the heat from the exhaust air from a building and transfers it to the supply/fresh fresh air entering the building to preheat the air and increase overall heating efficiency.

The quantity of heat necessary to raise the temperature of a specific mass of a substance by one degree.

Alternating current in which three separate pulses are present, identical in frequency and voltage, but separated 120 degrees in phase.

A building design that uses structural elements of a building to heat and cool a building, without the use of mechanical equipment, which requires careful consideration of the local climate and solar energy resource, building orientation, and landscape fe ...

A type of window glass that contains special tints that cause the window to absorb as much as 45% of incoming solar energy, to reduce heat gain in an interior space. Part of the absorbed heat will continue to be passed through the window by conduction and ...

A space heating device that burns pellets; are more efficient, clean burning, and easier to operate relative to conventional cord wood burning appliances.

A device that releases pressure within a radiator when the pressure inside exceeds the operating limits of the vent.

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

The ratio of the radiant energy (heat) leaving (being emitted by) a surface to that of a black body at the same temperature and with the same area; expressed as a number between 0 and 1.

The wheeling of electric power in amounts and at prices that generally have been negotiated in longterm contracts between the generator and a distributor or very large consumer of power.

The total diffuse and direct insolation on a horizontal surface, averaged over a specified period of time.

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 amount of heat introduced to a space from all heat producing sources, such as building occupants, lights, appliances, and from the environment, mainly solar energy.

The process of managing the consumption of energy, generally to optimize available and planned generation resources.

The thermodynamic cycle that is an ideal standard for comparing performance of heat-engines, steam power plants, steam turbines, and heat pump systems that use a condensable vapor as the working fluid; efficiency is measured as work done divided by sensib ...

A company or individual that is not directly regulated as a utility. These entities produce power for their own use and/or sell it to regulated utilities.

The alignment of a building along a given axis to face a specific geographical direction. The alignment of a solar collector, in number of degrees east or west of true south.

An electrical inverter that inverts direct current electricity to alternating current electricity, and that uses another alternating current source, such as an electric power transmission and distribution network (grid), for voltage and frequency referenc ...

The change in heat content that occurs with a change in phase and without change in temperature.