The prescribed level of pollutants allowed in outside or indoor air as established by legislation.

The visible portion of the electromagnetic spectrum with wavelengths from 0.4 to 0.76 microns

A heat storage system that uses a heat storage medium, and where the additional or removal of heat results in a change in temperature.

The maximum load that a device is capable of carrying.

An air heater in which air is blown over electric resistance heating coils.

see Peak Power

An incorporated right, liberty, privilege, or use of another entity's property, distinct from ownership, without profit or compensation; a right-of-way.

A diagram that indicates the average percentage of time that the wind blows from different directions, on a monthly or annual basis.

The natural, convective movement of air or water due to differences in temperature. In solar passive design a thermosyphon collector can be constructed and attached to a house to deliver heat to the home by the continuous pattern of the convective loop (o ...

A unit of electrical capacitance; the capacitance of a capacitor between the plates of which there appears a difference of 1 Volt when it is charged by one coulomb of electricity.

The amount of visible light that passes through the glazing material of a window, expressed as a percentage.

A measure of air purity that is equal to one complete air change (in an interior space).

Solid fuels made from primarily wood sawdust that is compacted under high pressure to form small (about the size of rabbit feed) pellets for use in a pellet stove.

A curve that indicates the number of hours per year that specific wind speeds occur.

A thermal storage wall is a south-facing wall that is glazed on the outside. Solar heat strikes the glazing and is absorbed into the wall, which conducts the heat into the room over time. The walls are at least 8 in thick. Generally, the thicker the wall, ...

A device for converting mechanical energy to electrical energy.

A federal agency established in 1933 to develop the Tennessee river valley region of the southeastern U.S., and which is now nation's largest power producer.

Air brought into a building from outside to replace exhaust air.

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

A layer of semiconductor material, such as copper indium diselenide or gallium arsenide, a few microns or less in thickness, used to make solar photovoltaic cells.