Consist of three main layers. The top layer is near ambient and has low salt content. The bottom layer is hot, typically 160 F to 212 F (71 C to 100 C), and is very salty. The important gradient zone separates these zones. The gradient zone acts as a tran ...

A combustion heating appliance that vents the combustion by-products directly into the heated space. The latest models have oxygen-sensors that shut off the unit when the oxygen level in the room falls below a safe level.

A device that moves and/or circulates air and provides ventilation for a room or a building.

A building structural element that is built onto a building's exterior along the inner edges of all the windows, and extending from the ground to the eaves. Wingwalls help ventilate rooms that have only one exterior wall which leads to poor cross ventilat ...

An air distribution outlet, typically located in the ceiling, which mixes conditioned air with room air.

The weight of a material per unit of volume compared to the weight of the same volume of water.

To disconnect a transmission and/or distribution line; a power line that is not carrying a current; to open a circuit.

A unit of apparent power, equal to 1,000 volt-amperes; the mathematical product of the volts and amperes in an electrical circuit.

The area between the layers of glazing (panes) of a window.

In reference to solar energy systems, the angle that a solar collector is positioned above horizontal.

The conversion of the complex carbohydrates in organic material into energy.

A pump for circulating the heat transfer fluid in a hydronic heating system.

That portion of supply air that is drawn from outside, plus any recirculated air that has been treated to maintain a desired air quality.

A material used to seal areas of potential air leakage into or out of a building envelope.

A component of a hydropower plant; a pipe that delivers water to the turbine.

A colorless, pungent, gas (NH3) that is extremely soluble in water, may be used as a refrigerant; a fixed nitrogen form suitable as fertilizer.

Energy available as a result of motion that varies directly in proportion to an object's mass and the square of its velocity.

A method of preventing oxidation of the exposed metal in structures by imposing between the structure and the ground a small electrical voltage.

The transformation on a compound or material into one or more substances by heat alone (without oxidation). Often called destructive distillation. Pyrolysis of biomass is the thermal degradation of the material in the absence of reacting gases, and occus ...

The amount of power a wind turbine can produce at its rated wind speed, e.g., 100 kW at 20 mph. The rated wind speed generally corresponds to the point at which the conversion efficiency is near its maximum. Because of the variability of the wind, the amo ...