How are heating degree-days calculated?

Heating degree-days are calculated by subtracting the average daily temperature from a specified base temperature, commonly set at 18° C (or 65° F), which represents a threshold for heating needs. This method reflects the demand for heating in a given location and time period.

The idea behind this calculation is to estimate how much heating is required to maintain an indoor environment at a comfortable temperature as outdoor temperatures drop. Each degree below the base temperature signifies a higher demand for heating, hence, for every degree the average temperature is below 18° C, one heating degree-day is recorded.

This approach is essential for energy providers and consumers to assess heating requirements over time, allowing them to gauge energy consumption and costs more effectively. By using this standardized method, it provides a consistent measure for comparing heating needs across different locations and periods.