dd Heating Degree-days is a unit of measure for calculating the effect of temperature on the consumption of energy (e.g. heating oil) to heat a location, essentially the opposite of Cooling Degree-days.
A unit measuring the extent to which the outdoor mean daily dry-bulb temperature (average of maximum and minimum) falls below 18o Celcius for each calendar day on which such deficiency occurs. (On the Fahrenheit scale, the assumed reference temperature is 65o.)
A measure of how cold a location was over a period of time, relative to a base temperature. In CBECS, the base temperature used is 65 degrees Fahrenheit, and the period of time is one year. The heating degree-day is the difference between that day’s average temperature and 65 degrees if the daily average is less than 65; it is zero if the daily average temperature is greater than or equal to 65. Heating degree-days for a year are the sum of the daily heating degree-days for days that year.
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.
A measure of how cold a location was over a period of time, relative to a base temperature. In this report, the base temperature used is 65 degrees Fahrenheit and the period of time is 1 year. The number of heating degree-days for a single day is the difference between the base temperature and the day's average temperature, if the daily average is less than the base; it is zero if the daily average temperature is greater than or equal to the base temperature. The number of heating degree-days for a longer period of time is the sum of the daily heating degree-days for days in that period. Annual heating degree-days averaged over 30 years from 1961 to 1990 are called Normal Heating Degree-Days. Average daily temperature is the mean of the maximum and minimum temperatures for a 24-hour period. Heating degree-days can also be calculated using a base temperature other than 65 degrees. The computation is performed in an analogous manner.