British thermal unit (Btu)

The amount of heat required 1) to raise the temperature of 1 pound of water 1 degree Fahrenheit or 2) to raise the temperature of 1 cubic foot of air 55 degrees Fahrenheit or 3) to raise the temperature of 55 cubic feet of air 1 degree Fahrenheit.


Btu Factor

The heat within natural gas. This factor, which is determined by the supplier, changes daily and is a measurement of gas quality. This number is printed on the customer’s bill each month.


Cubic feet (cf)

A measurement used for volume or capacity at sea level and 60 degrees.


Efficiency rating

The percentage of effective or useful energy output from the total energy input.


Energy Codes

An Energy Code consist of several structural calculations that measure how energy efficient the home is. The amount of exposed wall, the square footage, the amount of window/glass and the R value of the insulation are among these calculations. The state of Florida requires both an energy code and manual J to be done before a building permit will be issued. Okaloosa Gas will provide a residential Energy Code free of charge to anyone that request one, all that is needed is a full set of building plans/blueprints. Request forms may be found on the Okaloosa Gas web site, or obtained at any Okaloosa Gas payment center. Manual J’s should be provided by the HVAC contractor who will be supplying the home with heating and air conditioning.



1 MMBtu is equal to 1,000,000 Btu’s or 10 therms.


Kilowatt hour (kwh)

The energy equivalent of 3,412 Btu’s of power used in one hour or one thousand watts of power being used in one hour.



A measurement used for a stack of wood, hay or straw.



The equivalent of 100,000 Btu’s or 95 cubic feet of natural gas.

Definitions and Terms