A thin, reflective foil sheet that exhibits low radiant energy transmission and under certain conditions can block radiant heat transfer; installed in attics to reduce heat flow through a roof assembly into the living space.

The enclosure on a water heater, furnace, or boiler.

A thin sheet of semiconductor (photovoltaic material) made by cutting it from a single crystal or ingot.

A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).

The highest energy band in a semiconductor that can be filled with electrons.

The deposition of thin films of semiconductor material by the evaporation of elemental sources in a vacuum.

The geographical direction that the primary or largest exterior wall of a building faces.

A metal rod placed in a water heater tank to protect the tank from corrosion. Anodes of aluminum, magnesium, or zinc are the more frequently metals. The anode creates a galvanic cell in which magnesium or zinc will be corroded more quickly than the metal ...

The combining of rooms in a structure according to similar heating and cooling patterns. Zoning requires using more than one thermostat to control heating, cooling, and ventilation equipment.

A type of florescent light ballast that uses a magnetic core to regulate the voltage of a florescent lamp.

The component of an electric motor composed of solid bars (of usually copper or aluminum) arranged in a circle and connected to continuous rings at each end. This cage fits inside the stator in an induction motor in channels between laminations, thin flat ...

The utilization of solar energy through photosynthesis.

A form of movable insulation that uses tiny polystyrene beads blown into the space between two window panes.

An optical, ultrasonic, or infrared sensor that turns room lights on when they detect a person's presence and off after the space is vacated.

An architectural element for shading windows and wall surfaces placed on the exterior of a building; can be fixed or movable.

Combination of two power plant turbine cycles utilizing two different working fluids for power production. The waste heat from the first turbine cycle provides the heat energy for the operation of the second turbine, thus providing higher overall system e ...

Energy storage using electrochemical batteries. The three main applications for battery energy storage systems include spinning reserve at generating stations, load leveling at substations, and peak shaving on the customer side of the meter.

An alternative path. In a heating duct or pipe, an alternative path for the flow of the heat transfer fluid from one point to another, as determined by the opening or closing of control valves both in the primary line and the bypass line.

A means of reducing the volume of a material by compaction into a bale.

The amount of energy (in electron volts) required to free an outer shell electron from its orbit about the nucleus to a free state, and thus promote it from the valence to the conduction level.