Thermal bridges of living wall systems

Abstract

Many parameters of living wall systems were investigated within the last years. It has been established that living wall systems reduce the urban heat island effect, bind dust and reduce noise pollution. Also the effect of the living wall system on the thermal insulation of the façade has been explored. But until now, there has not been any investigation on thermally well insulated facades. The thermal bridges were neglected in all published research until now. In the present paper this research gap has been taken up. Two living wall systems had been installed on three different façade types. One of them is thermally insulated, the other two are not. Long term measurements at the not thermally insulated facades showed an additional heat resistance value between 0.12 m² K/W and 0.39 m² K/W due to the living wall systems, while neglecting thermal bridges. The period of measurement was between 1st Mai 2015 and 31st March 2019. They have been calculated for the three investigated facades and two living wall systems by using AnTherm. For the anchoring devices two different scenarios were calculated. In one scenario the anchoring devices were made out of aluminum and in the other one they were made out of stainless steel. It turned out that the thermal bridges can not be neglected when it comes to thermally insulated facades. At the thermally insulated facades, the ΔU-Value ranges between 0.01 W/(m² K) and 0.08 W/(m² K). It cannot be neglected and ought to be taken into consideration.