Effects of climate changes on building energy demand and thermal comfort in Canadian offce buildings adopting different temperature setpoints Mr Pouriya Jafarpur, Dr Umberto Berardi * Ryerson University, 350 Victoria St, Toronto, ON, M5B 2K3, Canada A R T I C L E INFO Keywords: Climate change Building performance simulation Future weather fle Energy demands Temperature setpoints Thermal comfort ABSTRACT Offce buildings are responsible for a substantial portion of the energy demand in the commercial sector. To better understand and address the impacts of climate change on their energy demand and comfort levels, this paper investigates offce buildings located in extremely cold, cold-humid, and cool-humid Canadian climate zones. Building energy simulations are performed using climate projections for the 2056–2075 period. The effect of extending thermostat setpoints, as a demand response strategy on reducing energy demand, is also studied under future climate conditions. The results quantify the expected decrease in the heating and the increase in the cooling loads due to the future warmer temperatures across Canada. However, the magnitude of change varies signifcantly among the three selected climate zones. In fact, extending the temperature setpoints would reduce the annual energy demand by 0.9–8.7% in Quebec City, 1.6–9.1% in Toronto, and 1.4–9.9% in Vancouver. For all three selected cities, extending the temperature setpoints result in a substantial percentage of zones with a predicted mean vote (PMV) outside of the ±0.5 range. The benefts of increased levels of insulation for reaching thermal comfort during cold winter days and the penalty that would occur in summer days are assessed. Finally, the greenhouse gas emissions for the present and forecasted future energy demand of heating and cooling are determined. 1. Introduction The environmental and social impacts of climate change have prompted countries worldwide to commit to reducing their greenhouse gas (GHG) emissions. Among the actions taken to cut GHGs, great attention has been reserved for the building sector [1]. In fact, more than 30% of total global energy use and 19% of the total GHG emissions are attributed to buildings [2]. Furthermore, buildings are regarded as particularly vulnerable to the impacts of heatwaves and climate change as the energy needs for maintaining a comfortable indoor environment are strongly linked to the external climatic conditions [3]. In Canada, buildings have one of the highest energy intensities of any other end-use sector, due to the harsh climate and historically inade- quate energy-saving practices. For instance, the residential and com- mercial building sectors accounted for 13% and 12% of total end-use energy demand, respectively [4]. The energy-use growth per year of 1.4% in the commercial sector from 1970 to 2017 represented the largest among all sectors in Canada. Indeed, it is expected that the building energy demand will continue to increase at an average rate of 0.6% annually in the coming decades [4]. Within the commercial building sector, offces represent the largest percentage of energy use (35.2%) and GHG emissions (34.7%) [5], and thus they were selected as the focus of the present study. A substantial portion of the energy use in offce buildings is for space heating and cooling, making the heating, ventilation, air conditioning (HVAC) system critical in reducing their energy use intensity while providing thermal comfort conditions for building occupants [6]. Studies have shown that improvements in thermal comfort are associ- ated with enhanced occupant performance, productivity, and health, making the goal of reaching thermal comfort increasingly crucial [7–9]. Thermal comfort is infuenced by many factors, both environmental and personal. The most signifcant environmental factors, infuencing oc- cupants’ thermal comfort, since Fanger’s studies in the 1970s, are air temperature, mean radiant temperature, air velocity, and relative hu- midity [10]. Changes in the climate due to global warming have direct impacts on the HVAC energy demand, sizing, and its ability to maintain the indoor temperature within comfortable temperature ranges. Consequently, given the lifetime of a building, there is a need to consider future climate projections in modelling building design and code compliance [11]. As demand response programs that manage peak demands become * Corresponding author. E-mail address: uberardi@ryerson.ca (D.U. Berardi). Contents lists available at ScienceDirect Journal of Building Engineering journal homepage: www.elsevier.com/locate/jobe https://doi.org/10.1016/j.jobe.2021.102725 Received 3 March 2021; Received in revised form 4 May 2021; Accepted 11 May 2021