Paper Conference

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


A theoritical framework for the integration of a green roof model in ESP-r

Aloysius Decruz, Georgios Kokogiannakis, Jo Darkwa, Paul Strachan, Jun Hong

Abstract: Green roofs are increasingly used in low energy buildings because of their potential in reducing energy use, improving thermal comfort, mitigating heat island effect and managing storm water. An accurate evaluation of a green roof is important in order to assess the energy and carbon impact from introducing them in the building fabric. It has been found that the currently available tools are either stand-alone programs or are not fully accounting for the dynamic interactions of heat and moisture exchanges in green roof layers. The objective of this paper is to outline the theoretical framework of on-going research that aims to integrate a green roof model within the ESP-r whole building energy simulation program. The green roof model is based on the finite volume approach to simultaneously solve energy and moisture balance equations within control volumes, which represent and couple the various layers of the green roof. In line with the ESP-r structure, the Crank-Nicolson scheme of discretised equations is used. These are solved locally so that the results can be used in the integrated whole building simulation engine of ESP-r.
Pages: 9 - 16