The amount of heat energy needed to raise the temperature of a given mass of a substance by one degree Celsius. The heat required to raise the temperature of 1 kg of water by 1 degree Celsius is 4186 Joules.

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.

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

The grilled opening into a room by which the amount of warm air from a furnace can be directed or controlled; may include a damper.

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

A type of hydroturbine in which the entire generator is mounted inside the water passageway as an integral unit with the turbine. These installations can offer significant reductions in the size of the powerhouse.

A material that retards the movement of water vapor through a building element (walls, ceilings) and prevents insulation and structural wood from becoming damp and metals from corroding. Often applied to insulation batts or separately in the form of treat ...

Biomass converted directly to energy or converted to liquid or gaseous fuels such as ethanol, methanol, methane, and hydrogen.

A unit of electrical force equal to that amount of electromotive force that will cause a steady current of one ampere to flow through a resistance of one ohm.

An ideal substance that absorbs all radiation falling on it, and reflecting nothing.

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- ...

see Air-Source Heat Pump.

A material or structural element that inhibits air flow into and out of a building's envelope or shell. This is a continuous sheet composed of polyethylene, polypropylene, or extruded polystyrene. The sheet is wrapped around the outside of a house during ...

A standard unit of electrical power equal to one thousand watts, or to the energy consumption at a rate of 1000 Joules per second.

The process of determining energy consumption, by various techniques, of a building or facility.

A condition that results from an imbalance between the number of protons and the number of electrons in a substance.

In reference to solid biomass fuels, such as wood, having zero moisture content.

A structural, load-carrying building member with an open web system that supports floors and roofs utilizing wood or specific steels and is designed as a simple span member.

Describes the reliability of power plants. It refers to the number of hours that a power plant is available to produce power divided by the total hours in a set time period, usually a year.

The total cost of production divided by the total quantity produced.