Carleton University’s clean energy solution

By Leah Den Hartogh

Change is uncomfortable. When new practices are brought into the workplace, it is natural to feel a bit of resistance. It is easier to stay with what you know. But contrary to popular belief, old dogs can learn new tricks.

Back in 2021, the Canadian government committed to achieving net-zero emissions by 2050 as part of its Canadian Net-Zero Emissions Accountability Act. According to the federal government’s website, this would mean that the Canadian economy either emits zero greenhouse gas emissions or offsets its emissions. This could look like planting trees or implementing technologies that can capture carbon before it is released.

Recently, Carleton University in Ottawa, Ont. announced the creation of its new research facility and program called the Centre for Advanced Building Envelope Research (CABER). The program focuses on the advancement of residential and commercial building envelope materials and designs. “How can we really try to push the research forward and look at innovative ways to retrofit buildings because there’s 14 million dwellings that already exist in the built environment. Seventy per cent of those are older than 30 years old, so they don’t meet the same energy efficiency requirements that are prescribed in the building code. How can we then address those types of homes that do need to be ready to be retrofitted?” explains Cynthia Cruickshank, director of CABER.

This could include retrofitting from the outside of a building, rather than from the traditional method from the inside, reports Cruickshank. That way there would be less disruption for the occupants during the renovation. It could also include super-thin insulation materials, prefabricated construction, and panelized retrofits.

Specialized equipment

The lab has specialized equipment like a guarded hot box — a cube with an internal chamber that’s wired with sensors. Using data from the box, the team of researchers will be able to calculate a wall’s ability to resist the transfer of heat. A pressurized spray rack will also be used to assess the air and water tightness of the same wall samples.

For the guard box, Cruickshank and her team will be able to explore temperatures of around -35 C to 50 C. “Within the whole thing, we can evaluate many different scenarios all across North America and really, all around the world,” explained Cruickshank. The relative humidity can be changed from 10 to 90 per cent.

In addition, other experiments will determine based on how new and retrofit construction methods will impact things such as mould or rot. “We’re also looking at new construction as well; looking at new types of materials that maybe traditionally aren’t used in the built environment and then using some of those materials and trying to analyze them to determine if we are fixing something or are we providing a solution but now introducing another problem?” This will allow the team to determine where within the building heat loss is occurring.

The A Team

The research team will include 15 students and Cruickshank as the graduate supervisor. There are students from mechanical engineering, civil engineering, architecture, and engineering.

Cruickshank hopes to be able to work with colleges and tradespeople in the future with projects, “We need the people who are going to be on the ground building these homes,” she explains. “How can we retrofit homes in a sustainable and quick manner in a way that’s not disruptive and affordable? We can’t do this by ourselves. We need to really tap into all the different sectors and determine, what are your needs? What are your challenges? For example, what materials are you not comfortable with and why? Really make sure that we dig deep to find all that out.” She mentions that this project will benefit everyone within the trades and that it’s a bit of a two-way street. “We’re really learning together. They have skills and we do as well. It’s about working together towards better solutions and make sure that we all appreciate each other’s backgrounds and what challenges our understandings that we have,” explains Cruickshank.

The construction is complete on the research centre and all that’s left is to finish commissioning and instrumenting all the equipment necessary to collect their data. They have already built their first wall sample. Part of it is for calibration, explained Cruickshank. “We’re calibrating using samples that have properties that are fairly stable, so that we know what we should get as an answer. That way, we can verify that everything is working properly.”

Playing the long game

There will be six openings created along the walls of the building, which will allow for the researchers to put samples through long-term testing. Using the in-situ wall openings, they will be able to study thermal and occupant comfort, and also evaluate how the building envelope performs long-term when exposed to the elements.

The program is funded by two grants; the first is provincially through the Ontario Research Fund, which allowed the program to cover about half the expenses for the needed equipment. The second is for equipment and student funding, which comes from Natural Resources Canada through their Office of Energy Research and Development.

There is hope that some of the information gathered through their research will help push the building code and how buildings are built or retrofitted. “If the building code is moving towards low embodied carbon, this will contribute to that effort, and also contribute to climate change and reducing our greenhouse gases,” explains Cruickshank. “Buildings can still look really great, even with these retrofits. It’s more making sure that we understand what’s already in the wall and the points of failures that already exist.”

She notes that when improvements are made to the energy efficiency of the living space, its not something that can be easily seen. As such, there needs to be incentives to encourage homeowners to make retrofits. “When most homes are built to last only 60 to 70 years, we’re kind of pushing that with a lot of them now,” explains Cruickshank.

“Homeowners will need to make a choice. They can either tear down their house and build a new one, or they have to retrofit it.”
Carleton recently announced a new graduate building engineering program, which started this September. Many students expected to work with CABER will be part of that graduate program.