| Résumé | The aim of this study is to evaluate the impact of using hourly Marginal Emission Factors (MEF) for electricity consumption instead of annual Average Emission Factors (AEF) to estimate the operational GHG emission reductions of building retrofit measures in medium office buildings in Ontario, Canada. Considering the availability of MEFs, three cities located in different climate zones within the province of Ontario were selected for this study, i.e. Toronto (CZ5), Ottawa (CZ6), and Timmins (CZ7A). Operational carbon emissions were calculated by multiplying an emission factor by the annual consumption of each energy source required by the building, as specified in common carbon accounting methods such as the GHG Protocol and ISO 14064. Results show that the retrofit measures that have the highest potential to reduce operational GHG emissions of medium office buildings located in Ontario are: replacing the HVAC system, replacing windows, and reducing air leakage rate. The obtained results also indicate that the annual electricity MEF can be significantly higher than the AEF reported in the National Inventory Reports. This means that indirect emissions are significantly underestimated when using AEFs, compared to MEFs. Additionally, in cases where natural gas is used as primary heating fuel, the use of AEF overestimates the percentage of GHG emission reduction associated with fuel switching by up to 23% compared to cases where MEFs are used. |
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