What are heating degree days and cooling degree days?
Heating Degree Days and Cooling Degree Days are used for agricultural purposes, as well as other things. The formula to calculate these is simple; it is just the number of degrees the mean (average) temperature for the day departs from 65F. For example, if the high is 50F and the low is 30F, the mean would be 40F, and there would be 25 heating degree days (65-40). If the high is 90F and the low is 70F, the mean would be 80F, and there would be 15 cooling degree days (80-65).
Heating degree days are indicators of household energy consumption for space heating. It was found that for an average outdoor temperature of 65 degrees Fahrenheit, most buildings require heat to maintain a 70 degree temperature inside. Similarly, for an average outdoor temperature of 65 degrees or more, most buildings require air-conditioning to maintain a 70 degree temperature inside. How heating and cooling degree days are computed Take the high and low temperature for the day, and average them. If this number is greater than 65 F, then we have (Average temperature – 65) cooling degree days. If the average temperature is less than 65 degrees, then we have (65 – Average temperature) heating degree days. Running totals are kept for these units over a time period of a year so fuel distributors and power companies can assess average demands. Growing Degree Days Courtesy of Michigan State University Extension Growing degree day accumulations involve the amount of accumulated heat require
Heating degree days are indicators of household energy consumption for space heating. It was found that for an average outdoor temperature of 65 degrees Fahrenheit, most buildings require heat to maintain a 70 degree temperature inside. Similarly, for an average outdoor temperature of 65 degrees or more, most buildings require air-conditioning to maintain a 70 degree temperature inside. How heating and cooling degree days are computed Take the high and low temperature for the day, and average them. If this number is greater than 65 F, then we have (Average temperature – 65) cooling degree days. If the average temperature is less than 65 degrees, then we have (65 – Average temperature) heating degree days. Running totals are kept for these units over a time period of a year so fuel distributors and power companies can assess average demands. Source: http://www.wunderground.com/about/faq/degreedays.asp Dew Point All air contains water vapor of varying quantities. The dew point indicates
