A unit of measurement for the ability of a material to retard the diffusion of water vapor at 73.4 F (23 C). A perm, short for permeance, is the number of grains of water vapor that pass through a square foot of material per hour at a differential vapor p ...

Standardized weights or volumes for heating fuels.

A battery-powered electrically driven vehicle.

A device that tracks the movement of the sun; used to orient solar concentrating systems.

The effect of cooling by the radiation of heat from a building to the night sky.

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.

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

A construction element that inhibits termites from entering building foundations and walls.

A measure of the electrical resistance of a material equal to the resistance of a circuit in which the potential difference of 1 volt produces a current of 1 ampere.

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.

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

A device used to control temperatures; used to control the operation of heating and cooling devices by turning the device on or off when a specified temperature is reached.

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

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 unit used to rate the performance of a solar photovoltaic (PV) cells, modules, or arrays; the maximum nominal output of a PV device, in Watts (Wp) under standardized test conditions, usually 1000 Watts per square meter of sunlight with other conditions, ...

The discomfort or interference with visual perception when viewing a bright object against a dark background.

A device for converting continuous circular motion into reciprocating rectilinear motion.

A generic term for an electrical conductor.

A registered trademark name for houses built with tires, aluminum cans, and earth.

A heat exchanger for recovering heat from flue gases for heating water or air.