The influence of variations in base temperature over the calculated ventilation energy demand.

The heating degree-days method is widely used for calculation of the air change heating energydemand. However, different countries perceive different values for base temperatures due todifferent insulation levels and internal loads, decreased infiltration rates through tighterconstruction practices, and low temperature settings in efforts to reduce energy consumption.This has always made it difficult to make accurate comparisons for heating energy demandbetween different countries. In this study, the influence of variations in base temperature over thecalculated heating energy demand was investigated. The heating degree-days for three testbuildings were calculated by using different base temperatures i.e. 15, 16, 17, 18, and 20 C asperceived in different countries. The air change heating energy demand was computed by usingthe obtained heating degree-days. The results were analysed and an equation that can be used forrecalculation of the air change heating energy demand for alternative base temperatures wasderived. The results have clearly confirmed that even a difference of 1 C in base temperaturecan lead to a substantial difference in the calculated ventilation energy demand. The derivedequation makes it possible to recalculate the air change energy consumption to alternative basetemperatures and hence make comparisons among different countries.