Detailed assessment of embodied carbon of HVAC systems for a new office building based on BIM

Abstract

The global shift towards embodied carbon reduction in the building sector has indicated the need for detailed impact analysis across all its components and throughout the whole lifecycle of the building. The environmental impact of Heating, Ventilation, and Air conditioning (HVAC) systems has only slightly been studied, and most of the existing studies are based on assumptions and rule of thumb techniques.

In this study, the requirements and methods to perform a detailed Life Cycle Assessment (LCA) for HVAC systems based on Building Information Modelling (BIM) are assessed and framed for the first time. The approach of linking external product data information to objects using Visual Programming Language (VPL) is tested, and its benefits over the existing workflows are presented. The detailed BIM model of the newly built and highly sustainable Siemens International Headquarters office is used as a case study. In addition, detailed project documentation is used to check the plausibility of the calculated impact.

The LCA results show that the embodied impact of the HVAC is three times higher than the SIA 2040 targets, and three times higher compared to the building’s operational impact. Furthermore, it is shown that the embodied impact of the HVAC systems, according to the existing knowledge for the total embodied impact of office buildings, lies in the range of 15- 36%. Nevertheless, further research and similar case studies are needed to provide a robust picture of the embodied environmental impact of HVAC systems. This would contribute to setting stricter targets in line with the vision of decarbonization of the building sector.