A salt, sodium sulfate decahydrate, that melts at 90 degrees Fahrenheit; a component of eutetic salts that can be used for storing heat.

An instrument for measuring solar radiation.

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

Solar collector thermal performance ratings based on collector efficiencies, usually expressed in Btu per hour for solar collectors under standard test or operating conditions for solar radiation intensity, inlet working fluid temperatures, and ambient te ...

The minimum temperature at which combustion of a solid or fluid can occur.

A heating system that uses only outside air for combustion and vents combustion gases directly to the outdoors. These systems are less likely to backdraft and to negatively affect indoor air quality.

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

The rate of heat flow required to maintain a specific indoor temperature; usually measured in Btu per hour.

The price paid for goods or services at the time of a transaction; a price that has not been adjusted to account for inflation.

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

A coil of tungsten wire suspended in a vacuum or inert gas-filled bulb. When heated by electricity the tungsten "filament" glows.

The ratio of fuel energy input as heat per unit of net work output; a measure of a power plant thermal efficiency, generally expressed as Btu per net kilowatt-hour.

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

The process of cooling by which a heat absorbing media absorbs heat from one source and radiates the heat away.

Individual rooms or zones in a building where temperature is controlled separately from other rooms or zones.

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.

A house built using passive solar design techniques.

A valve used to mix heated water with cold in a heating system to provide a desired water temperature for end use.

The ratio of the percentage change in the quantity of a good or service demanded to the percentage change in the price.

The amount of heat that a material can absorb and store.