A few years ago, when Geoffrey Hay discovered that his energy-efficient home was still leaking a lot of heat, he didn’t just add weatherstripping. Using his own predicament as inspiration, the University of Calgary geography professor made thermal maps of nearly 38,000 homes in 29 northwest Calgary neighbourhoods.
The HEAT (Heat Energy Assessment Technologies) project is an unprecedented undertaking yielding unprecedented results. Thermal city data was initially collected over two nights in May 2012, using a low-flying plane and the TABI-1800 — a Calgary-made, state-of-the-art thermal infrared camera. Hay and his research team captured images of heat emitted from the surface of geographical features, including rooftops, roads and trees, then compared them to geographic information system data from the city, including property boundaries and house shapes and ages. Wasted heat, shown for small roof sections (image, right) and across entire neighbourhoods (graphic, below), was determined based on peaks in roof-surface temperature relative to the ambient air temperature. Each dwelling and neighbourhood was assigned a “HEAT Score” between 0 and 100 (see example, bottom). The lower the better: a score of 83, for instance, is high on the inefficiency scale, while 25 is moderately low. The next steps, says Hay, are to include every single-dwelling home in Calgary — nearly 300,000 more residences — followed by cities across Canada.
“This gives homeowners an accurate picture of where they and their neighbours are losing heat, how much that loss is costing — financially and in terms of greenhouse gas emissions — and what you can do about it,” says Hay. And the financial benefits of improving a house’s HEAT Score can be high: an average roof-temperature difference of about 1 C cooler can mean hundreds in annual savings (hundreds of thousands at a neighbourhood level). “Energy efficiency is the low-hanging fruit that people don’t talk about, because they can’t see it,” says Hay. “This map changes that.”
To explore the web-based HEAT project and for ideas about how to improve home heat-efficiency, visit saveheat.co.