Energy | How Is A "Heating Degree Day" Defined?
How is a "heating degree day" defined?
Early in the twentieth century, engineers developed the concept of heating degree days as a useful index of heating fuel requirements. They found that when the daily mean (average) temperature is lower than 65° Fahrenheit (18° Celsius), most buildings require heat to maintain a 70° Fahrenheit (21° Celsius) temperature. Each degree of mean temperature below 65° Fahrenheit (18° Celsius) is counted as "one heating degree day."
For every additional heating degree day, more fuel is needed to maintain a 70° Fahrenheit (21° Celsius) indoor temperature. For example, a day with a mean temperature of35° Fahrenheit (1.5° Celsius) would be rated as 30 heating degree days and would require twice as much fuel as a day with a mean temperature of 500 Fahrenheit (10° Celsius ; 15 heating degree days).
Source: Bair, Frank E. The Weather...
[The entire page is 152 words long]
Navigate
