A byproduct of low-temperature carbonization of a solid fuel.

A masonry or metal stack that creates a draft to bring air to a fire and to carry the gaseous byproducts of combustion safely away.

In refrigeration, an evaporating temperature of 5 degrees Fahrenheit (F), a condensing temperature of 86 degrees F., liquid temperature before expansion of 77 degrees F., and suction temperature of 12 degrees F.

The abrupt and large increase in electrical conductivity exhibited by some metals as the temperature approaches absolute zero.

A clear, colorless, very mobile liquid that is flammable and poisonous; used as a fuel and fuel additive, and to produce chemicals.

A lamp that consists of a sealed arc tube inside a glass envelope, or outer jacket. The inner arc tube is filled with elements that emit light when ionized by electric current. A ballast is required to provide the proper starting voltage and to regulate c ...

The force per unit area acting on the surface of a solid boundary parallel to the flow.

The actual power rating that is developed by a motor before losses occur.

A value that describes the ability of a material to conduct heat. The number of Btu that flow through 1 square foot of material, in one hour. It is the reciprocal of the R-Value (U-Value = 1/R-Value).

The nominal voltage for which a conductor or electrical appliance is designed; the reference voltage for identification and not necessarily the precise voltage at which it operates.

A term used to describe heat energy lost from a water heater tank.

The duct(s) of a forced air heating/cooling system through which heated or cooled air is supplied to rooms by the action of the fan of the central heating or cooling unit.

One horsepower provided over one hour; equal to 0.745 kilowatt-hour or 2,545 Btu.

The process by which water in air changes from a vapor to a liquid due to a change in temperature or pressure; occurs when water vapor reaches its dew point (condensation point); also used to express the existence of liquid water on a surface.

The production of hydrogen using a photoelectrochemical cell.

A mixture of substances that has a melting point lower than that of any mixture of the same substances in other proportions.

The average time a minority carrier exists before recombination.

A type of solar thermal collector that has tubes (pipes) that the heat transfer fluid flows through that are connected to a flat absorber plate.

The central heating or cooling system contains a fan that gets its air supply through these ducts, which ideally should be installed in every room of the house. The air from a room will move towards the lower pressure of the return duct.

A unit of work done by the force of one dyne acting through a distance of one centimeter.