Heat images on cold nights
“We are not going to send an inspector to every building,” says Lee. “So we had to develop a quick way to get a first estimate of the state of the building stock.”
They settled on a technique called infrared thermography. This requires infrared cameras to detect thermal bridges by visually identifying thermal breaks and anomalies before proceeding with a physical inspection.
On a practical scale, it means that Tardy walked around lower-income neighbourhoods over about a dozen nights in February and March with an infrared camera and captured thermal bridges — basically, images of heat leaving a dwelling.
Thermal imaging is not new. It has been used by contractors and building owners for decades. But Tardy and Lee say that by feeding the images into a model that automatically calculates building parameters, they can make the evaluation process of a building easier and even applicable at a neighbourhood level.
While the images do not give the full picture of the state of a building, they do provide the quick estimation tool Lee says helps provide an overall assessment. Many other variables, including the hours of sunlight, wind and temperature would also need to be included in a future model.
Scaling up measurements
But in the meantime, “We have something that is easily digestible by policy-makers and the general public,” he says. “If envelope performance data can be easily collected and processed, then information can easily be obtained for many buildings. This opens up the possibility of analysing buildings between each other or even between different neighbourhoods.”
Tardy and Lee believe that having an imperfect but ballpark reading of housing stock will achieve several goals, especially in Quebec. It will rationalize subsidies by helping homeowners and lower-income households offset much-needed renovation and insulation costs, leading to a happier, healthier and wealthier population. It would also reduce greenhouse gas emissions by cutting down on energy consumption. And it would free up electricity reserves for sale to the United States.
“We as a society have to ask, is energy a luxury or is it a public good?” says Tardy.
If it is a public good, as is the case in Quebec, he believes policy-makers should prioritize the issue of energy waste due to inefficiency. Having accurate information on the province’s state of its housing stock would help.
Read the cited paper: “Building related energy poverty in developed countries — Past, present, and future from a Canadian perspective.”