Effects of a Vertical Green Façade on the Thermal Performance and Cooling Demand: A Case Study of a Tube House in Vietnam

Traditional architecture has often applied greenery in the design to improve the thermal performance of indoor spaces. Such a bioclimatic approach is not often seen in the contemporary tube houses of Vietnam. Vietnamese architects recently started to focus more on greenery solutions for housing projects. However, the quantitative effects of plants on the building performance has not yet been investigated in Vietnam. This paper reports on an experiment to quantify the benefits of a vertical greening system for thermal performance and energy saving. A typical tube house in Hanoi was selected and two similar rooms were monitored during July and August, 2018. One of the rooms’ façades was covered by the climbing plant Bougainvillea. Outdoor and indoor temperature and energy for air-conditioning were measured for the two rooms to quantify the effect of the greenery on the existing aluminium shading device and a bare window. Results for the green façade showed that the difference between outdoor and indoor temperature can be as high as 8°C. In addition, the climbing plants helped to reduce the indoor temperature by around 1°C and thus cooling energy was saved by up to 35%.