A measure of the water vapor content of air.

The part of a solar thermal collector that receives the sun's radiant energy and transforms it into heat energy.

The component of a collector that absorbs the solar energy and distributes it to a storage tank or heat-delivery system. Liquid collector absorbers use tubes or heat pipes to transport the heat.

Alternating current (AC) is the cyclical flow of electrical current, reversing direction as it flows. It is the type of electrical current provided by utility companies.

A sun-dried earthen, un-compressed brick used for wall construction. Traditional adobe blocks are a standard 10"x14"x4" size.

Annual energy output. A turbine depends on the average windspeed of the site. Expressed in kilowatt-hour units of electrical energy per year, this is the most important indicator of the value of a tur [..]

An amp-hour (Ah) is one amp of current flowing for one hour. An amp-hour is the unit of measurement for capacity of a battery.

Authority having jurisdiction (AHJ) is an individual or organization who enforces codes and standards in a particular area, typically via plan review, granting permits, and performing inspections.

A material or structural element that inhibits air flow into and out of a building's envelope or shell. Often it allows water to diffuse through it. See also Vapor Barrier.

The uncontrolled infiltration or exfiltration of air into buildings through cracks and joints in any building section, and around windows and doors of a building, caused by temperature or pressure dif [..]