LCA of net-zero energy residential buildings with different HVAC systems across Canadian climates: A BIM-based fuzzy approach

Abstract

The urgency of addressing building energy consumption's impact on climate change, particularly from fossil fuels, is of great significance. This study investigates the environmental and economic aspects of different climatic conditions in Canadian regions throughout a building's life cycle. Focusing on HVAC systems, choice between electricity, natural gas and solar sources. Using whole building life cycle assessments and energy simulations, the research examines 36 scenarios, considering three popular HVAC systems with six weather conditions. To reduce uncertainties, the study employs BIM and fuzzy-based methods. The results identified consistent environmental impacts across scenarios, averaging 1.4 tonnes CO2eq/m2 in GHG, 1.74 kg/m2 in PM2.5, and 3.61 kg/m2 in SO2 emissions for a typical net-zero energy building in Canada. Variations primarily result from operational, embodied, and transportation stages, rather than other life cycle stages. Colder climates, like central Canada, exhibit higher energy demands and increased global warming potential. Ground Source Heat Pump (GSHP has lower emissions despite higher upfront costs and is preferred when considering both environmental and economic factors. However, in mild climates like Vancouver, Air Source Heat Pump (ASHP) is optimal. Photovoltaic panels enhance HVAC system feasibility across various options. The study provides insights for building industry stakeholders, including designers, owners, and policymakers.