Degree Day (deg da) 1
Degree Day (deg da) 1 :
A unit used in meteorology and engineering to measure the demand for heating or cooling. In the United States, it's agreed that 65 oF (18.3 oC) is the critical outside temperature; below this tempeature heating is needed and above it cooling is needed. The number of degree days recorded on a given date is equal to the difference between 65 and the mean temperature for that date (figured as the average of the highest and lowest temperatures). If the mean temperature is above 65, cooling degree days (CDD) are recorded; if it is below 65, heating degree days (HDD) are recorded. The total number of heating or cooling degree days recorded in any period of time measures rather accurately the demand during that time for fuel used in heating and cooling buildings
