Assessing the validity of European labels for energy efficiency of heat pumps

Elsevier, Journal of Building Engineering, Volume 18, July 2018
Nolting L., Steiger S., Praktiknjo A.
The European Union implemented Ecodesign and Labelling Directives to support the market diffusion of energy efficient products. Accurate signals for consumers on energy efficiency (EE) are essential, as disinformation might lead to sub-optimal market allocations. Considering complex devices such as heat pumps (HPs), a conflict between simplicity of calculation on the one hand and accuracy on the other hand arises. For this reason, main differences on EE between real working conditions and test procedures carried out according to regulations are examined within this study: Firstly, the most important deviations between the test procedure and the current state of the art are presented. Secondly, their influence on the validity of HP labels is investigated using spreadsheet calculations and a MODELICA simulation model. The results indicate that the omission of important influence factors – such as local conditions and the applied control strategy – in the regulations leads to significant differences between reality and labelling. The band of uncertainty found within this study covers high deviations of + 80% to − 24% from the label value. Therefore, we provide several recommendations to mitigate these deviations and to optimize the information content of the label. Among these are the implementation of a higher spatial resolution of climate conditions, the consideration of higher insulation standards, and the inclusion of effects caused by price-driven controls of the HP unit.