A system where heat is supplied to areas of a building from a single appliance through a network of ducts or pipes.

The water content of a substance (a solid fuel) as measured under specified conditions being the: Dry Basis, which equals the weight of the wet sample minus the weight of a (bone) dry sample divided by the weight of the dry sample times 100 (to get percen ...

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.

A light control device that allows light levels to be manually adjusted. A dimmer can save energy by reducing the amount of power delivered to the light while consuming very little themselves.

The quantity of heat required to change the temperature of one unit weight of a material by one degree.

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.

All the natural and living things around us. The earth, air, weather, plants, and animals all make up our environment.

A solid-state electrical device that converts light directly into direct current electricity of voltage-current characteristics that are a function of the characteristics of the light source and the materials in and design of the device. Solar photovoltai ...

A type of anaerobic digester that has a mechanical mixing system and where temperature and volume are controlled to maximize the anaerobic digestion process for biological waste treatment, methane production, and odor control.

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

A combustion heating appliance in which heat is captured from the burning of a fuel for distribution, comprised mainly of a combustion chamber and heat exchanger.

Electric power plant or utility capacity on line and running at low power in excess of actual load.

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

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

The outer casing of a window that sits in a designated opening of a structure and holds the window panes in place.

A water heater that releases hot water from the top of the tank when a hot water tap is opened. To replace that hot water, cold water enters the bottom of the tank to ensure a full tank.

A heat source, such as a space heater, used to provide more heat than that provided by a primary heating source.

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 ...

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 device that reduces the pressure of liquid refrigerant thereby cooling it before it enters the evaporator coil in a heat pump.