A type of furnace in which fuel is spread, automatically or mechanically, across the furnace grate.

An electrically charged atom or group of atoms that has lost or gained electrons; a loss makes the resulting particle positively charged; a gain makes the particle negatively charged.

A small groove scribed into the surface of a solar photovoltaic cell which is filled with metal for contacts.

A column of gas at standard conditions of temperature and pressure (32 degrees Fahrenheit and one atmosphere).

A thermostat that can be set to automatically lower temperatures in an unoccupied house and raise them again before the occupant returns.

The temperature that a system is designed to maintain (inside) or operate against (outside) under the most extreme conditions.

A smaller version of standard fluorescent lamps which can directly replace standard incandescent lights. These lights consist of a gas filled tube, and a magnetic or electronic ballast.

The demand on an energy producing system; the energy consumption or requirement of a piece or group of equipment.

A type of heating appliance that performs more than one function, for example space and water heating.

The process of burning; the oxidation of a material by applying heat, which unites oxygen with a material or fuel.

An open-loop solar heating system in which the heat transfer fluid from the collector loop and the piping drain into a drain whenever freezing conditions occur.

The amount of energy absorbed (or converted) by a solar collector (or photovoltaic cell or module) over a 15 minute period.

A general term for the visible and near visible (ultraviolet and near-infrared) electromagnetic radiation that is emitted by the sun. It has a spectral, or wavelength, distribution that corresponds to different energy levels; short wavelength radiation ha ...

A thermodynamic property of a substance, defined as the sum of its internal energy plus the pressure of the substance times its volume, divided by the mechanical equivalent of heat. The total heat content of air; the sum of the enthalpies of dry air and w ...

Materials that prevent or slow down the movement of heat.

A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements. These lights have the best Color Rendition Index (CRI) of the High-Intensity Discharge lamps. They can be used for commercial interior lightin ...

Technologies that pertain to the generation of electricity.

An electrical device that resists electric current flow.

The value or purchasing power of a dollar that has not been reduced to a common basis of constant purchasing power, but instead reflects anticipated future inflation; when used in computations the assumed inflation rate must be stated.

A plastic foam insulation product, pressed or extruded into board-like forms, used as sheathing and insulation for interior basement or crawl space walls or beneath a basement slab; can also be used for exterior applications inside or outside foundations, ...