Canadian Consulting Engineer


March 1, 2008
By John Leckie

With environmental concerns high on every-one's radar these days, a growing area of practice for consulting engineers could be in performing energy audits to help homeowners cut their consumption of h...

With environmental concerns high on every-one’s radar these days, a growing area of practice for consulting engineers could be in performing energy audits to help homeowners cut their consumption of heating and cooling energy.

Don Fugler, P. Eng. is an example of someone who has been involved in this area of building research for 20 years. A mechanical engineer and senior researcher for sustainable housing for Canada Mortgage and Housing Corporation, he has made a significant contribution to this field in Canada.

The plastic bag approach

One of Fugler’s biggest contributions has been his ability to find a simple way of discovering where a problem exists.

An example is his simple garbage bag test to measure airflows through ducts and registers.

“If I get a call from someone who says, ‘My bedroom is cold,’ I can have them create an air flow measuring device while we are talking on the phone,” Fugler says. “I tell them to get a simple green garbage bag, seal it over the vent and time how long it takes to inflate the bag. That way you can tell if it is a distribution or an insulation problem. If the distribution is adequate, then you are dealing with a heat loss problem.”

Some testing equipment can be notoriously difficult to keep in calibration, with hygrometers used for measuring relative humidity high on the list. To test if these devices are in calibration, Fugler uses a mixture of salt and water and a sealed Ziplock bag. If the hygrometer does not read 75 per cent in that environment, it needs to be recalibrated.

At CMHC, Fugler has also tested a lot of alternative house types, like straw bale houses. The prevailing view when straw bale houses were being developed was that they did not have the same moisture problems as conventional housing. Fugler questioned that thinking and came up with an inexpensive method of testing a large number of the homes, using wood chips with a couple of screws or pins across them, and wires leading out to measuring equipment. He found that straw bale houses experience many of the same moisture problems as other types of housing.

Ice damming has been a major problem for homes in Canada. It occurs when heat escapes from a poorly insulated attic, melting the snow on the roof, which then flows down to an area of the roof where it collects and freezes. Moisture then backs up from the ice dam, getting under shingles and causing leaks in the roof.

“The easiest way to tell if you have a problem is to look at your roof after a light snow or a heavy frost,” Fugler says. “If there is a pattern where the snow or frost is melted off, that will let you know where the heat is escaping from your attic.”

Need for climate specific research

The problem of ice damming is one reason why Fugler favours retaining Canadian research institutions. There is still a strong need for climate-specific and housing-type research, he says.

“I talk at a lot of conferences about ice damming,” he says, “But once you get south of Ohio, no one has ever heard of it.”

Some materials are used differently in different climates. Take polyethylene, which we use as a vapour barrier. “In our [Canadian] houses it is on the inside surface, but if you get down close to Florida it is on the outside surface. If you mess it up you can run into big problems quickly.”

Fugler says that in the U. S. they talk about saving 10 to 20 per cent on their heating bills by sealing air-ducts. “What people don’t know about the 10 per cent savings is that the research was done on houses where the heating ducts are in the attic. With a few exceptions, no Canadian houses are built that atrociously,” Fugler says.

Recently, he carried out a study to see what would induce homeowners to improve the energy efficiency in their homes and reduce greenhouse gas emissions. He found that even with a 5 or 10 year payback, homeowners were still reluctant to do anything.

Education and voluntary programs are not enough, Fugler concludes. Regulation has to be increased to the point that conventional furnaces are no longer available and only high-efficiency appliances are on the market. Only then, will there be major improvements, he says.

Last fall, Fugler received the Beckie award from the Ontario Building Envelope Council, recognizing his efforts to improve building envelope science.

John Leckie is a freelance writer based in Toronto.


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