University of Saskatchewan

September 19, 2014   

U of S Innovation Could Decrease Building Energy Use

Blake Erb (photo by Anne-Marie Cey)
October 06, 2009

By Rory MacLean

For close to a decade, engineers at the University of Saskatchewan have been working on an energy exchange system for improved building ventilation that could recover up to 60 per cent of the energy required to condition air.

The exchanger could drastically reduce energy bills of Canada’s schools, hospitals and office buildings.

Engineering student Blake Erb built the first successful prototype of the energy exchanger as part of his master’s thesis which he will defend in October. This past summer, Erb presented a paper on the exchanger at a major international conference of engineering professionals in the ventilation field in Louisville, Kentucky.

The system is primarily for commercial use and should be available for production within the next few years.

“It really has the potential to impact the environment in a big way in terms of energy consumption,” said Erb, who is one of seven graduate students currently working on the project.

The system is called a liquid-to-air energy exchanger. It works by transferring heat and moisture between the air leaving and entering a building.

In winter, cold, dry air enters a building and needs to be heated and humidified. At the same time, warm, moist air is coming out of a building’s exhaust. The energy exchanger uses a salt solution to capture the heat and moisture from the air leaving to condition the cold, dry air coming in.

In the summer, the exchanger works in reverse, using the cool, dry air coming out of a building’s exhaust to cool and dehumidify the warm summer air being drawn in.

While there are other systems available to do this, the system Erb has been working on has a distinct advantage.

“The supply and exhaust streams are totally separated so you have a lower risk of contaminating the fresh supply air,” said mechanical engineering professor Carey Simonson, Erb’s supervisor along with professor emeritus Robert Besant.

Because the energy exchanger uses fluid to conduct energy between the air intake and exhaust, the system makes it easier to retrofit buildings compared to other models.

“If the supply and exhaust ducts are not close to each other, you can bring in this system and connect them with pipes,” Simonson said.

Considering that about half the energy used in a building goes to conditioning air, Erb says the potential energy savings are significant.

But the energy savings are just one benefit. Quality air pays off in the workplace, too.

According to Erb, productivity is linked directly to air quality and, with Canadians spending 90 per cent of their time inside, having an efficient way of conditioning air becomes a significant issue.

Erb already has had three journal articles cleared for publication. He has recently been awarded an NSERC (Natural Sciences and Engineering Research Council) graduate doctoral scholarship worth $35,000 per year but has declined the scholarship in order to take a job with Venmar CES Inc. a Saskatoon company that is a partner in the project.

Erb was involved with the project as an undergraduate too, having spent two summers on the project through an NSERC undergraduate research award.

Simonson describes Erb as a very well-rounded student. “He has a good blend of academic skills, but also very good practical skills in terms of getting things to work in a lab,” he said.

Erb feels this has been a rewarding project. “It has a real-world application and a big impact on energy consumption in a building,” he said.

The project is also a good fit for the engineering college which has “a long history of building science and heating, ventilating, and air conditioning research,” said Simonson. It also demonstrates the “strong partnership with industry that we like to have in the college,” he said.


Rory MacLean is a U of S student working with the SPARK (Students Promoting Research Knowledge) program of the U of S research communications office.

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