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

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.

The maximum heat output (in Btu per hour) released by a burner with a stable flame and satisfactory combustion.

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.

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

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

A measure of the heating requirements of a building expressed in Btu per degree-day.

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 ...

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

Electromagnetic radiation in the wavelength range of 4 to 400 nanometers.

A popular term for "non-conventional" transportation fuels derived from natural gas (propane, compressed natural gas, methanol, etc.) or biomass materials (ethanol, methanol).

An interior wall made of water filled containers for absorbing and storing solar energy.

A device that cools air by removing moisture from it.

The maximum load that a motor is capable of supplying.

Discharging a battery to 20 percent or less of its full charge capacity.

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

A slender threadlike spike of pure crystalline material, such as silicon.

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

A program of the U.S. Department of Energy (DOE) that implements energy legislation and presidential directives. FEMP provides project financing, technical guidance and assistance, coordination and reporting, and new initiatives for the federal government ...