Paper Conference

Proceedings of SimBuild Conference 2012: 5th conference of IBPSA USA


Thermal Performance of Three-Dimensional Building Envelope Assemblies and Details for Improving the Accuracy of Whole Building Performance Simulation

Christian Cianfrone, Neil Norris, Patrick Roppel, Medgar Marceau
Morrison Hershfield Limited, Vancouver, BC
Morrison Hershfield Corporation, Seattle, WA

Abstract: Thermal bridging through insulation layers in the building envelope reduces the thermal performance of building envelope assemblies and heat flow through thermal bridging can have a detrimental impact on whole-building energy performance. So, it is important for energy modelers, building engineers, and architects to consider the effects of thermal bridging when evaluating the expected performance of building envelope details and when designing building envelopes for energy efficient buildings. However, it is difficult to determine how much heat flows through thermal bridges using typical approaches, such as the area-weighted average of U-values, especially when dealing with three-dimensional (3D) heat flow paths. In ASHRAE Research Project 1365 (RP-1365), a methodology was developed, using a calibrated 3D model, that enables designers to account for heat flow through thermal bridges in a simple and practical manner. This approach can improve the accuracy of whole building performance simulations where complex thermal bridging is often ignored. This paper will provide an overview of RP-1365 and its potential impact on energy simulation. The impact on whole building energy performance will be examined for three building types in four different climates.
Pages: 83 - 95