Investigating the Energy Footprints of Conventional Façade Systems in comparison to Modern Multi-layered Façade Systems

Open Access
Author:
Chatterji, Neeraj
Graduate Program:
Architecture
Degree:
Master of Architecture
Document Type:
Master Thesis
Date of Defense:
May 08, 2012
Committee Members:
  • Ute Poerschke, Thesis Advisor
Keywords:
  • Life Cycle Assessment
  • Thermal Simulations
  • Energy Footprint
  • Multi-layered Façade Systems
  • Building Materials
Abstract:
Although building designers typically use components based on prescribed R- Values and U-Values from the manufacturers, the selection of components does not guarantee higher performance. Thus, the goal of this work is to challenge the use of R- Values and U-Values as a measure of selecting wall systems and to find out to what extend high-performance façade systems are efficient. Furthermore, the analysis aims to reveal the contribution of each material within a façade system based on resource usage and guide towards an alternate selection of façade systems. With architects and researchers pursuing iterative paths of analysis, synthesis and evaluation in achieving sustainable solutions, the breaking down of a problem largely occurs in isolation. This work presents a method based on coupling of two different types of computational models that analyzes the energy footprints of conventional to high performance multi-layered façade systems. These models are: building energy simulation model and life cycle assessment model. The method has been demonstrated on four wall systems: (1) Brick masonry cavity wall system with interior finishes (2) Straw Bale Construction (3) Exterior insulation and finish systems wall construction (4) Multi-layered wall system with vacuum insulation, for a climate type 5A (ASHRAE Standards 90.1-2004 and 90.2-2004 Climate Zone) and humid continental type climate with hot summers, cold winters and lack of a dry season (Köppen Classification). With the assumption of no energy recovery at the end of the materialsʼ lives and no replacement of the facade systems, the results indicate that the energy content of the multi-layered wall system with vacuum insulation does not overcome that of any conventional wall system within the first 21 years of the operational use. Therefore, a key finding of the thesis is that facade systems having a low embodied energy or a higher thermal performance do not automatically have better performances during their lifetimes.