Dynamic heat transfer model of vertical green façades and its co-simulation with a building energy modelling program in hot-summer/warm-winter zones

Cooling demand dominates the energy consumption of buildings in hot-summer/warm-winter zones. Vertical green façades (VGFs) are an effective design strategy to reduce the cooling load in these regions. Many studies have investigated the cooling benefits of VGFs; however, the lack of accurate and low-cost co-simulation methods limits their application as it is difficult for architects and engineers to use them to evaluate the energy consumption of buildings. To address this issue, we developed a dynamic heat transfer (DHT) model for VGFs based on the Beer–Lambert Law and Penman–Monteith Equation. We then proposed a co-simulation approach for VGFs with EnergyPlus by using an additional heat source term and energy management system . We subsequently conducted field measurements to validate the accuracy of the DHT model and the reliability of the co-simulation approach. Finally, we created simulation scenarios in four typical cities in the hot-summer/warm-winter zone of China and analysed the effects of a VGF on the cooling load of an office building. The results indicated that the VGF reduced the room cooling load by 11.7–18.4%. Furthermore, improving the wall insulation only led to a 0.3–8.4% reduction in the room cooling load. Moreover, the cooling load saving rates of rooms with a VGF and well-insulated walls were 6.6–15.8%. Our research is likely to prove useful to future researchers investigating VGFs using DHTs and building designers attempting to effectively incorporate VGFs into architectural plans. • We proposed an approach for co-simulation of VGFs and EnergyPlus. • Effect of a VGF on the cooling load of a building was investigated. • VGFs on west-facing walls contributed to maximum cooling load savings. • VGF shading and transpiration reduced cooling load more than adding wall insulation. • Cooling load saving rate from VGFs decreased upon enhancing wall insulation.