It’s a fact of high-rise life that’s become all too familiar to legions of urban condo dwellers: many apartment buildings leak like sieves, with heating or cooling seeping out through poorly sealed windows, cracks and concrete balcony slabs.
Yet those construction flaws, in the aggregate, add up to something much larger and more problematic. By most estimates, buildings today account for about 40% of all carbon emissions, and therefore play a huge role in the accelerating climate crisis. We should be thinking of all those drafty apartments as if they were gas-guzzlers spewing carbon and other harmful gases into the atmosphere.
In many ways, the solutions to building-related carbon emissions are way less high tech than the gear required to run an electric vehicle. We also know where to find the sources. According to Omid Alaei, vice-president of QEA Tech, a 25-employee Markham engineering firm, as much as 50% of a building’s energy losses involve the so-called building envelope: windows, exterior walls, balconies, doors, and so on.
In low-rise residential structures, these leaks aren’t especially difficult to locate using conventional scanning techniques. Apartment buildings, by contrast, are far more difficult to accurately assess.
To remedy the problem, QEA Tech’s engineers developed a thermal imaging software system that can be loaded onto a digital camera-equipped drone. It flies around the exterior of a building, taking pictures to create what a three-dimensional heat map. The algorithm detects areas where there seems to be excessive heat loss and compares these to the so-called R values of those portions of the building – i.e. the rated insulation value of a particular window or segment of exterior wall.
When the system notices a significant difference, QEA Tech’s technology not only pinpoints the places where the leaks are occurring but also estimates the return on investment associated with a retrofit. Alaei cites one building where the drones located a piece of wall that was missing insulation. The annual cost of the heat loss was about $2,000 while the installation of the replacement insulation set the property owner back by just $500 – a clear win. (The scans themselves range in price from about $5,000 to $30,000, depending on the size of the building).
Such scans, he adds, have become increasingly popular among property managers working for insurance companies and other institutional investors purchasing multi-unit residential buildings. “We’re targeting high rises because there’s no [other] solution for that,” Alaei says.
Toronto journalist John Lorinc writes about cities, sustainability and business.