AL-01

(Oral presentation, session Areas and Living, 13.50 - 14.10 hrs)

Driven by the need to reduce the energy use of the built environment, European governments enforce increasingly stringent requirements on the energy performance of newly built and renovated buildings.

Buildings are awarded an energy label based on a theoretically calculated energy use to benchmark the energy performance of the building stock. However, several authors [1,2] report that the theoretical energy use can deviate significantly, up to a factor 3 [2], from the energy use as measured in practice.

Considering that, in the Netherlands, space heating amounts to approximately two-thirds of the final energy demand of residential buildings [3], the performance of the building envelope, defining the heat losses, is the one important building component for improving the actual energy performance of a building.

In this study, the actual thermal performance of a case study building in Enschede, in terms of the total heat loss coefficient (HLC), is determined by performing a co-heating test. The HLC includes both transmission and ventilation heat losses [4]. To distinct between these two, air infiltration and exfiltration rates are measured prior to and after the co-heating test by means of a blower door test.

The measured transmission losses are compared with the theoretical thermal transmittance values of the case object’s thermal shell. Conclusions are drawn on the thermal quality of the dwelling relative to (1) legal requirements and (2) agreements between the contractor responsible for retrofitting the dwelling and the owner of the building (e.g. energy label, RC-values) .

References

[1] Entrop, A. G., Brouwers, H. J. H., & Reinders, A. H. M. E. (2010). Evaluation of energy performance indicators and financial aspects of energy saving techniques in residential real estate. Energy and Buildings, 42(5), 618–629. https://doi.org/10.1016/j.enbuild.2009.10.032

[2] Struck, C., Benz, M., Dorer, V., Frei, B., Hall, M., Ménard, M., … Sagerschnig, C. (2014). Performance Gap in der Schweiz - Brisanz, Ursachen und Einflüsse auf die Differenz von geplantem Energiebedarf und dem gemessenen Verbauch von Gebäuden. In Status-Seminar: Forschen für den Bau im Kontext von Energie und Umwelt (pp. 1–10).

[3] Eurostat. (2016). Household energy consumption per dwelling by end-use. Retrieved April 17, 2018, from https://www.eea.europa.eu/data-and-maps/daviz/energy-consumption-by-end-uses-2#tab-chart_1

[4] Bauwens, G., & Roels, S. (2014). Co-heating test: A state-of-the-art. Energy and Buildings, 82, 163–172. https://doi.org/10.1016/j.enbuild.2014.04.039