Professor Dr. Christer Harrysson lectures at the Örebro University (Sweden) and is Director of Bygg & Energiteteknik AB

Professor Dr. Christer Harrysson is a well known researcher who lectures on Energy Techniques at the Örebro University in Sweden. He has conducted extensive research into the energy consumption of different energy systems, sources and emitters.

Prof. Dr. Christer Harrysson

Research is one of the most important tools for increasing knowledge and obtaining a clear, independent insight into the functions of different heating distribution systems. It also makes it possible to rank the performances of a variety of solutions. In my research, I studied the energy used by 130 houses in Kristianstad, Sweden over a one-year period. Their electricity, hot water and heating system energy consumption were all closely monitored. All the houses were built between mid-1980s and 1990, and were grouped in six distinct areas, with variations in construction, ventilation and heating systems. The results were convincing. We recorded differences of up to to 25% in energy use between the different technical solutions in use.

My main objective was to determine the difference between energy efficiency of different types of heating systems and the thermal comfort these systems offer. We compared the recorded results of underfloor heating and radiators, and conducted interviews with residents. We found that homes heated with radiators used a lot less energy. In total – including the energy for the heating system, hot water and household electricity – the average energy consumption measured was 115 kWh/m². This was in comparison to the average use of energy of 134 kWh/m² in homes with underfloor heating. In short, our data shows radiators to be 15-25% more efficient than underfloor heating. Measurement data also shows that the 15% difference correlates with houses that have underfloor heating with 200mm ESP insulation beneath the concrete floor tiles.

Conclusion

The most important and significant finding of this study is that designers, suppliers and installers need to apply their skills and provide residents with clear and transparent information. In addition to that, we found the level of comfort to be as important as the calculated energy performance and consumption of new, but also renovated buildings. This is something that should be taken into account not only by project planners and constructors, but also by the owners and facility managers of new buildings.

Note: Houses in the study are directly comparable with the buildings insulated according to the German EnEV 2009 regulations.

A complete summary of the research conducted by Professor Harrysson can be found at www.purmo.co.uk/clever