The value or purchasing power of a dollar in a specified year carried forward or backward.

The lower or net heat of combustion for a fuel that assumes that all products of combustion are in a gaseous state. (See Net Heating Value below.)

see Peak Watt.

Pounds/force per square inch absolute.

The conversion of electric power to visible light by using an electric charge to excite gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produc ...

The time of the day, at a specific location, when the sun reaches its highest, apparent point in the sky; equal to true or due, geographic south.

The period marked by successive crossing of the earth's meridian by the sun; the hour angle of the sun at a point of observance (apparent time) is corrected to true (solar) time by taking into account the variation in the earth's orbit and rate of rotatio ...

The process by which sunlight directly enters a building through the windows and is absorbed and stored in massive floors or walls.

The two times of the year when the sun is apparently farthest north and south of the earth's equator; usually occurring on or around June 21 (summer solstice in northern hemisphere, winter solstice for southern hemisphere) and December 21 (winter solstice ...

A tax credit granted for specific types of investments.

A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.

The ratio of the sum of the noncoincidental maximum demands of two or more loads to their coincidental maximum demands for the same period.

The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.

The potentially useful byproducts of ethanol fermentation process.

The fine particulate matter entrained in the flue gases of a combustion power plant.

The amount of solar energy that passes through a glazing material, expressed as a percentage.

The region between an n-layer and a p-layer in a single material, photovoltaic cell.

The total distribution of electromagnetic radiation emanating from the sun. The different regions of the solar spectrum are described by their wavelength range. The visible region extends from about 390 to 780 nanometers (a nanometer is one billionth of o ...

A coating applied to the surface of the glazing of a window to reduce heat transfer through the window.

Freshly cut, unseasoned, wood.