OpEEr – Optimising the energy efficiency of buildings through individual room temperature control

Abstract

In Switzerland, the standard SIA 384/1 (based on SN EN 12828) does not require individual room temperature control for new buildings or very well refurbished buildings with space heating supply temperatures below 30 °C. This is justified by the so-called “self-regulating effect”, which means that when the room temperature increases the heat input into the room is reduced due to the decreasing temperature difference between the hydronic heating system and the room. According to the new regulations of the Swiss cantons (MuKEn 2014), at least a reference room temperature control is prescribed. However, it is still unclear whether and when the individual cantons will adopt this regulation. This study compares the three most common variants for room temperature control using dynamic simulations. The simulations show that the self-regulating effect cannot sufficiently reduce the heat input into the room, and that a reference room control is not only energetically more efficient, but also economically more attractive. Individual room control performs better than reference room control in terms of comfort and final energy consumption. A further finding from the project is that the heat requirement for an apartment of a multi storey building depends strongly on the temperatures with which the storeys below and above are heated. Under certain circumstances, the ratio of the total building heat requirement for an apartment of the storey in the middle can be reduced from 20% to 1%. In the project, recommendations for building owners and authorities regarding room temperature control were worked out.