# Glossary

**Ampere** - The unit of measurement of electrical current produced in a circuit by 1 volt acting through a resistance of 1 Ohm.

**British thermal unit (BTU)** - The quantity of heat required to raise the temperature of 1 pound of liquid water by 1 degree Fahrenheit at the temperature at which water has its greatest density (approximately 39 degrees Fahrenheit).

**Cooling degree-day (CDD)** - A measure of how warm a location is over a period of time relative to a base temperature, most commonly specified as 65 degrees Fahrenheit. The measure is computed for each day by subtracting the base temperature (65 degrees) from the average of the day's high and low temperatures, with negative values set equal to zero. Each day's cooling degree-days are summed to create a cooling degree-day measure for a specified reference period. Cooling degree-days are used in energy analysis as an indicator of air conditioning energy requirements or use.

**Kilowatt** - a common metric unit of power, equivalent to 1000 watts.

**Heating Degree Day (HDD)** – A measure of how cold a location is over a period of time relative to a base temperature, most commonly specified as 65 degrees Fahrenheit. The measure is computed for each day by subtracting the average of the day's high and low temperatures from the base temperature (65 degrees), with negative values set equal to zero. Each day's heating degree-days are summed to create a heating degree-day measure for a specified reference period. Heating degree-days are used in energy analysis as an indicator of space heating energy requirements or use.

**ITS** – The Department of Information Technology Services.

**PAC** – President’s Advisory Council

**Set-Point** – A guideline that is established to control the internal temperature of a building. The federal government recommended guidelines for heating and cooling is 68 degrees in the winter, and 78 degrees in the summer. The estimated dollar savings per 1 degree change in set-points is 5%.

**Therm** - A commercial unit of heat energy. One therm is equal to 100,000 Btu.

**Volt** - The International System of Units (SI) of electric potential or electromotive force.

**Watt** – The unit of electrical power equal to one ampere under a pressure of one volt. A watt is equal to 1/746 horsepower.

**Source** – Energy Information Administration