Glossary of electric industry, energy & cooperative terms

H

Heat Exchanger
A device used to transfer heat from one medium to another, as from water to air.

Heat Gain
The increase in the amount of heat contained in a home, as a result of sunshine, warm air leakage, warming of the walls and roof, and heat given off boy people and equipment.

Heat Loss
The decrease in the amount of heat contained in a home, resulting from heat flow through walls, windows, and roof; and air leakage through many parts of the building envelope.

Heat Pump
An energy device that both heats and cools a home. In winter, it extracts heat from the outside and transfers it inside; in the summer it absorbs heat from indoors and transfers it out-of-doors.

Heat Recovery/System
A device used to capture a portion of the expelled heat from an air conditioner or heat pump compressor to be used for domestic water heating. The device is in essence providing "free" water heating and replaces conventional water heating sources when in use.

Heating Seasonal Performance Factor (HSPF)
A measure of average annual heating efficiency of a heat pump. A minimum HSPF of 6.8 is recommended.

Heavy Oil
The fuel oils remaining after the lighter oils have been distilled off during the refining process. Except for start-up and flame stabilization, virtually all petroleum used in steam plants is heavy oil.

Hertz (Hz)
Cycles per second, an international unit of measurement.

Hydroelectric Plant
A facility that produces electric energy by releasing water from a reservoir through generators. Short form is hydro.

Hydroelectric Power
The process of producing electric energy from the kinetic energy in flowing water. Water, generally stored behind a dam, is allowed to run downhill past the blades of the turbine, making them rotate. The turbine shaft, in turn, is connected to a generator that produces electricity.

Hip Roof
A roof that rises by inclined planes from all four sides of a building.

HTML
Hypertext Markup Language. It is the programming language for static Web pages. It usually includes hypertext links between related objects and documents.

HTTP
Hypertext Transfer Protocol. It is a standard method of transferring data between a Web server and a Web browser.

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Page last updated: Friday, March 5, 2010