A Building in a Heatwave

Michael Pullinger

Canada's all-time temperature records were shattered during a heatwave in BC earlier this week. Climate experts are pointing to a clear signature of climate change in these heat records.

While there will rightly be a lot of attention on the tragic loss of life and wildfires caused by the heat wave, we thought it would be worthwhile sharing some data we gathered during the event.

Several of the data sensors we use for our building energy assessments were not deployed on any client project sites this week. So, we took the opportunity to track the progress of the record breaking 39.5 degrees in and around Michael Pullinger's private residence starting at approximately 5 pm on July 27.

Being lucky enough to be in an air-conditioned building has obvious benefits in a heatwave. We can see the difference in temperature between the air-conditioned living room and the office space which is not so lucky. This has serious implications in a place like BC where many residential buildings in particular are not currently air-conditioned. If (as predicted by many climate scientists) heatwaves like this become more frequent, what will need to be done just in terms of upgrading our building stock to adjust to the new reality of a changing climate?

But, heat is not always distributed equally. A building space whose temperature approaches the mid-30s during a heatwave is one thing. But, some surfaces can be much hotter, as can be seen by the south-facing concrete patio which reached a surface temperature of almost 70 degrees. The south-facing windows clearly push far more heat into the building through solar heat gains than would occur for windows with well-configured shading. Any black surfaces (such as the rubber welcome mat) are likely to get dangerously hot under these conditions.

On the flip side, a heatwave is an opportune time to use infrared imaging to assess the performance of a building envelope. Usually we complete such investigations during the winter when the cold outdoor conditions highlight problematic areas, but the heatwave clearly showed some areas where insulation has been poorly installed, and repairs could reduce winter-time heating bills (or summer-time air-conditioning where available). The office here is actually a garage converted by a previous home owner, so some of the 'gaps' in the existing insulation are clear.

Something else to notice is the comparison to the nearest weather station (Victoria International Airport). While only approximately 8 km away (as the crow flies), some differences are apparent. This highlights that while energy modelling and simulation of buildings often use a nearby weather station as a 'proxy' for the climate of a building location, there will always be some discrepancy. This will become even more important as the 'historical' weather data become less representative of the future climate a building will experience over its lifetime.

Our commitment to clean energy solutions is driven by a desire to help reduce greenhouse gas emissions that contribute to climate change. Nevertheless, these past days show that climate change is already here, and further changes are unavoidable. Even in a place like BC, where the climate has long been considered "mild", adaptations will need to be made to reduce the impacts of climate changes that we are already experiencing.