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.

A method of predicting heating and/or cooling loads using instantaneous load calculation at different outdoor dry-bulb temperatures, and multiplying the result by the number of hours of occurrence of each temperature.

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

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.

Microorganisms that live in oxygen deprived environments.

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

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.

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

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

An interior court to which rooms open.

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

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

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

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

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

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

The use of direct, diffuse, or reflected sunlight to provide supplemental lighting for building interiors.

A graph that indicates the distribution of wind speeds as a function of the cumulative number of hours that the wind speed exceeds a given wind speed in a year.