Savings of up to 10.7% and, on average, up to 5.9% in the residential building’s heating energy consumption. These excellent results were obtained by Kimmo Hilliaho in his study of the balcony glazing’s energy-economical effects at the Tampere University of Technology in August 2010.
The research was conducted in Finland and supplemented with reference calculations from Germany. The heating energy consumption of glazed and unglazed balconies was compared by using field measurements and computer simulations. In addition, it was ascertained how the balcony type, thermal insulation and direction affect temperatures on the glazed balconies.
The results show that taking compensation air from a glazed balcony will clearly increase energy savings arisen from the glazing. In the best case, glazed balconies function as efficient windboxes, enabling owners to reduce temperature by as much as 1°C in the rooms adjacent to their balconies. This allows the owners to save energy and increase their living comfort.
The glazing of recessed balconies (with walls on both sides) is often a more efficient energy-saver than the glazing of protruding balconies (L- or U-shaped). The savings for south-side balconies are slightly higher than those for the balconies facing towards other directions. However, the savings gained by both types are substantial. An inspection of the tightness of glazing revealed that the size of the gaps between glass panes does not have much impact on energy savings. Crucial is how residents use their balcony glasses.
In most cases, Finns know the energy-economically best way of using their balcony glazing: glass panes must be kept closed in winter and open in summer. However, detailed instructions are useful to maximize savings.
The research was supplemented with energy calculations carried out in such element houses in Berlin that were comparable to Finnish houses under research.
Heating energy savings gained through the use of balcony glazing varied in Berlin from 5.6% to 12.0%. Glazing solutions were most beneficial to buildings with balconies facing towards south and compensation air taken through the balcony. Taking supply air from the balcony, instead of taking it directly from outside, was the factor that had the most distinct impact on energy savings. On average, heating energy savings in Germany amounted to 8.2%, which is even more than in Finland.
Keeping the building base in good condition and management costs on a reasonable level has a direct impact on housing costs − and satisfaction of the residents. In addition to living comfort, properly used first-rate balcony glazing systems provide residents and apartment owners with pure financial benefits.
The conclusion drawn from the research results published in Tampere was clear: providing all high-rise blocks built in the 1960s and 1970s with balcony glazing really pays off. Substantial savings could also be obtained in new high-rise blocks with a compensation air intake through the glazed balcony. Besides energy savings, balcony glazing could bring about other substantial financial benefits. According to the research made by D.Sc. (Tech.) Jussi Mattila, providing the balconies with glazing has an impact on the buildings’ general condition, as this action can postpone the renovation need of balconies by s total of 6-10 years!