Degree days is a term used to indicate the heating or cooling needed for any certain day.
It is calculated from a temperature of 65 degrees. (It should be noted that the standard conditions temperature is 68 degrees.) The degree day is computed by taking the mean of the highest temperature and the lowest temperature for a day and subtracting it from 65.
Example: The lowest recorded temperature for a certain day was 28 F. (degrees)
The highest recorded temperature for the same day was 36 F. (degrees)
The mean temperature for the day was
28 + 36
2 - 31 degrees
65 -32 = 33 degree days.
Degree days may be added by weeks, months or for a season to give a comparison of the heating needs for different years.
Tags:
Basics of Refrigeration