A graph that indicates the distribution of wind speeds as a function of the cumulative number of hours that the wind speed exceeds a given wind speed in a year.

The use of direct, diffuse, or reflected sunlight to provide supplemental lighting for building interiors.

A fan mounted on an attic wall used to exhaust warm attic air to the outside.

The process of decomposing biomass with anaerobic bacteria to produce biogas.

A device that converts the mechanical energy of rotation into electricity based on electromagnetic induction. An electric voltage (electromotive force) is induced in a conducting loop (or coil) when there is a change in the number of magnetic field lines ...

That fraction of annual energy demand supplied by a solar system.

An opening; in solar collectors, the area through which solar radiation is admitted and directed to the absorber.

A wall that carries ceiling rafters or roof trusses.

The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit; equal to 252 calories.

The process of removing a power plant, apparatus, equipment, building, or facility from operation.

The temperature of a medium, such as gas or liquid, which comes into contact with or surrounds an apparatus or building element.

Referring to alterations in the environment due to the presence or activities of humans.

A mechanical device used for air circulation and to provide cooling.

A measure of seasonal or annual efficiency of a central air conditioner or air conditioning heat pump. It takes into account the variations in temperature that can occur within a season and is the average number of Btu of cooling delivered for every watt- ...

A unit for measuring the extent that the outdoor daily average temperature (the mean of the maximum and minimum daily dry-bulb temperatures) falls below (in the case of heating, see Heating Degree Day), or falls above (in the case of cooling, see Cooling ...

The control of the quality, quantity, and temperature-humidity of the air in an interior space.

A category of electric power producer established under the Public Utility Regulatory Policy Act (PURPA) of 1978, that includes small-power producers (SPP) who use renewable sources of energy such as biomass, geothermal, hydroelectricity, solar (thermal a ...

The positive pole or electrode of an electrolytic cell, vacuum tube, etc. (see also sacrificial anode).

A movable plate used to control air flow; in a wood stove or fireplace, used to control the amount and direction of air going to the fire.

A building architectural element (vestibule) with two airtight doors that reduces the amount of air infiltration and exfiltration when the exterior most door is opened.