A type of motor designed to operate precisely at the synchronous speed with no slip in the full-load speeds (rpm).

An electricity powered device that extracts available heat from one area (the heat source) and transfers it to another (the heat sink) to either heat or cool an interior space or to extract heat energy from a fluid.

States that energy cannot be created or destroyed, but only changed from one form to another. First Law efficiency measures the fraction of energy supplied to a device or process that it delivers in its output. Also called the law of conservation of energ ...

A type of water heater that circulates water through a heat exchanger in a boiler. The heated water then flows into an insulated storage tank.

A wood-burning appliance for space and/or water heating and/or cooking.

The amount of useful energy produced by a system less the amount of energy required to produce the fuel.

One thousand kilowatts, or 1 million watts; standard measure of electric power plant generating capacity.

The amount of heat introduced to a space from all heat producing sources, such as building occupants, lights, appliances, and from the environment, mainly solar energy.

An elementary particle of an atom with a negative electrical charge and a mass of 1/1837 of a proton; electrons surround the positively charged nucleus of an atom and determine the chemical properties of an atom.

The heat that flows from the building interior, through the building envelope to the outside environment.

A type of water heater that has no storage tank thus eliminating storage tank standby losses. Cold water travels through a pipe into the unit, and either a gas burner or an electric element heats the water only when needed.

A measure of the efficiency of converting a fuel to energy and useful work; useful work and energy output divided by higher heating value of input fuel times 100 (for percent).

A configuration of an electrical circuit in which the voltage is the same across the terminals. The positive reference direction for each resistor current is down through the resistor with the same voltage across each resistor.

An electrical inverter that inverts direct current electricity to alternating current electricity, and that uses another alternating current source, such as an electric power transmission and distribution network (grid), for voltage and frequency referenc ...

A building energy auditing technique for locating areas of low insulation in a building envelope by means of a thermographic scanner.

A hydrocarbon gas obtained from underground sources, often in association with petroleum and coal deposits. It generally contains a high percentage of methane, varying amounts of ethane, and inert gases; used as a heating fuel.

The unit price of a good or service estimated from some base year in order to provide a consistent means of comparison.

The ratio of the minimum amount of work or energy required to perform a task to the amount actually used.

A house built using passive solar design techniques.

A seal used to prevent the leakage of fluids, and also maintain the pressure in an enclosure.