C11 -- Whole-Life Carbon Assessment of HVAC Systems for Nearly Zero Energy Buildings

Carbon-neutral targets have been set for construction industry in many regions including the European Union (EU). With the recent recast of Energy Performance of Buildings Directive (EPBD) in 2021, whole-life carbon assessment is being favoured as a method to analyze the carbon emissions throughout the lifetime of buildings. The focus is now on the embodied carbon emissions, whereas the operational carbon was dominant in the last decade. Several countries such as Netherlands, France and Denmark initiated new limits on the embodied carbon of new buildings. On the other hand, there is not a standard description for the scope of such assessments. For whole-life carbon assessment of a building, the minimal scope generally includes the envelope and structure whereas finishes, fittings and technical services are not mandatory. As the expectations for nZEBs increase, the impact of HVAC systems on the operational carbon emissions becomes crucial. On the other hand, the hidden impact of such systems on embodied carbon needs to be investigated. Then, this study adopts a case study approach on office buildings in Turkiye and calculates the embodied carbon of high-performing technical systems which meets the requirements of nZEB regulation. Several technical systems were compared in four different climate zones.