Implement the vertical greenery wall (facade) to multi-stored building in Sri Lankan context

Abstract

The use of vertical greening has an important impact on the thermal performance of buildings and on the effect of the urban environment, in both summer and winter. Plants are functioning as a solar filter and help to prevent the absorption of heat radiation of building materials extensively. Applying green façades wall (GFW) is not a new concept, where most of the developed countries have been implemented the vertical greenery to their buildings while realising its sustainable benefits. However, vertical greening can provide a cooling potential on the building surface, which is to be very important during summer periods in warmer climates. In this study, an analysis of the effect on temperature (air and surface) of vertical greening systems on the building level is presented. An experimental approach was set up to measure the temperature on direct and indirect GFW, using infrared thermometer and psychrometer. And the energy saving effect of the thermal resistance was identified by using heat transfer calculation. A comparison between measurements on a bare façade wall (BFW) and a GFW were done in the summer season to understand the contribution of vegetation to the thermal behaviour of the building envelope. Since the research was focused on quantifying the vertical greening systems and in the possible effect on the thermal resistance, the main conclusions that could be drawn from the selected buildings are presented. The evaluation was done in different locations, namely, in front of bare facade wall (BFW) and greened facade wall (GFW), and identified small differences of air temperature between façade walls. Further, it was investigated that inside and outside surface temperature of walls and finally concluded that the vertical greening systems are effective natural sunscreens, due to a reduction of the surface temperatures behind the green layer compared to the BFW. It was found that the energy recovering value between the BFW and GFW. The final result of energy requirement was less to the GFW than the BFW.