Illustration of the heat-insulating effect of a facade greening system in a simulation.

In the present article the investigations of a facade greening system concerning the thermal insulation is shown. It is a greening system which is made out of boxes and installed at an office building in Vienna. The office building has no thermal insulation and the facade is made out of solid bricks. Over a period of about two years, in situ U-value measurements were taken at two positions of the facade. One position is on the greened part of the facade, the other on the not greened part of the facade. The measuring points are located at the same floor, bordering on the same room and facing the same direction (southwards). The evaluation of the measurements shows that the U-value at the greened part of the facade is about 20 % less than at the non-greened one. The heat transfer resistance increases by 0.33 m(2)K/W. In the simulation program WUFI the situation was adjusted and the increase of the heat resistance value was -calculated dynamically. The comparison of the measured and simulated values shows that the extreme values of the measured values are more pronounced than the simulated ones. The heat transfer resistance increases by 0.25-0.27 m(2)K/W.