Paper Conference

Proceedings of ASim Conference 2012: 1st Asia conference of IBPSA-China, Japan, Korea


Simulating the energy performance of green roofs for Ningbo’s climate

Georgios Kokogiannakis, Jo Darkwa, Kate Yuan

Abstract: A passive means of lowering the energy demand and improving indoor thermal comfort in buildings is the application of green roof components. The complexity between the heat and moisture exchanges in green roof layers and the large variations of green roof types make the need for experimental or simulation assessments necessary in order to quantify the energy benefits from green roofs. In terms of simulation assessments, the current treatment of green roofs in simulation programs is either over-simplistic, for example by ignoring heat and moisture exchanges such as the evapotranspiration, or the more advanced models have limitations and require inputs that are rarely available in practice. In this paper a combination of experimental and modelling techniques are used to assess the potential heating and cooling load reductions from the application of green roofs in the subtropical climate of Ningbo in China. Experimental measurements of weather data and of temperatures across the layers of an existing green roof in Ningbo are taken and are then fed in the ESP-r whole building simulation program to modify the boundary conditions of the roofs on building models and run an integrated assessment for the energy performance of buildings with green roofs. The method provides a generalised assessment for the energy performance of green roofs in Ningbo by overcoming the limitations of existing green roof simulation models.
Pages: 94 - 101