A type of heating fuel derived by refining crude oil that has a boiling range at atmospheric pressure from 400 degrees to 550 degrees F.

The component of a combustion device that regulates the amount of air entering the combustion chamber.

A fluid, such as methanol or ethylene glycol, added to vehicle engine coolant, or used in solar heating system heat transfer fluids, to protect the systems from freezing.

A device, such as a steel plate, used to check, retard, or divert a flow of a material.

A combustible gas created by anaerobic decomposition of organic material, composed primarily of methane, carbon dioxide, and hydrogen sulfide.

Energy required to operate mechanical components of an energy system, or a source of energy or energy supply system to back-up another.

A thermodynamic cycle using constant pressure, heat addition and rejection, representing the idealized behavior of the working fluid in a gas turbine type heat engine.

A type of heat pump that transfers heat in outdoor air to water for space or water heating.

Microorganisms that live in oxygen deprived environments.

This is the voltage-ampere requirement of a device designed to convert electric energy to a non-electrical form.

An interior court to which rooms open.

The ratings under which specified appliances convert energy sources into useful energy, as determined by procedures established by the U.S. Department of Energy.

One quadrillion Btu. (1,000,000,000,000,000 Btu)

The presence of contaminants in the air in concentrations that prevent the normal dispersive ability of the air, and that interfere with biological processes and human economics.

The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.

The cost of producing electricity up to the point of the powerplant busbar.

The ratio of light reflected by a surface to the light falling on it.

A hard, dense type of coal, that is hard to break, clean to handle, difficult to ignite, and that burns with an intense flame and with the virtual absence of smoke because it contains a high percentage of fixed carbon and a low percentage of volatile matt ...

A measure of the flow of current (in amperes) over one hour.

A component of a heating or ventilation appliance used to conduct fresh air into, or waste air or combustion gases out of, an appliance or interior space.