Heating Degree Days
Fuel cost estimation made simple.
Heating Degree Days
A heating degree day is a measure of how cold it has been. When heating a space, fuel demand varies according to how cold it is. Degree day units were developed to help estimate the heat requirements and fuel costs for a building. When the outside air is above a certain temperature, no heat is required. This is what we refer to as a base temperature. 65° F is used as the base temperature for calculating heating degree days.
If you take the average daily temperature and subtract it from 65° F, you can determine your degree days. Each degree accounts for one degree day. If today's High temperature is 50° F and the Low is 30° F, our average daily temperature is 40° F. Subtract 40° F from 65° F, and you will see that there are 25 degree days for today. Heating costs are directly proportional to the number of degree days in a year.
If you take the average daily temperature and subtract it from 65° F, you can determine your degree days. Each degree accounts for one degree day. If today's High temperature is 50° F and the Low is 30° F, our average daily temperature is 40° F. Subtract 40° F from 65° F, and you will see that there are 25 degree days for today. Heating costs are directly proportional to the number of degree days in a year.
