by Vivian Belik
The Steve Cardiff home, which will temporarily house Yukoners living with HIV/AIDS, has already nabbed a lot of attention for its pint-sized proportions. It boasts all the necessities of a regular home in just 204 square feet.
What few people know is that the tiny house may also be one of the best insulated in Whitehorse. Lodged into the roof of the home is a thin, metal-foiled panel that has been vacuum-sealed shut.
Though it looks unassuming, the panel is actually a technological innovation. A single vacuum-insulated panel is two and a half times better at keeping out the cold than a standard 3.5 inch piece of fibreglass insulation. Yet it’s only half an inch thick.
The tiny home will be the first house in Whitehorse to sport the technology. It’s exciting, says Stephen Mooney, the Yukon Research Centre’s director of cold climate innovation.
The centre donated several vacuum-insulated panels (in addition to $10,000) for the construction of the home.
In the end, only a few panels were used because the layout of the home didn’t work with the panels’ fixed dimensions. But Mooney hopes the technology will take off in the Yukon.
He likens the panels to vacuum-sealed bags of coffee you might find in the grocery store. But instead of using plastic wrap, engineers use two thin sheets of metal foil, called mylar.
Long strands of polyester are placed between the mylar sheets to keep them apart. Then, the air is sucked out of the middle creating a vacuum and forming a hard membrane of insulation.
“It’s crazy insulative,” says Mooney.
The reason a vacuum works so well as an insulator is that it prevents the conduction and convection of heat away from a building. Heat is transferred through the interaction of air molecules. That’s why a vacuum – the absence of air molecules – greatly restricts this from happening.
A 3.5 inch piece of insulation that you might find in an average Riverdale home has an insulation R-value of 12. By comparison, the thin vacuum-sealed panel has an R-value of 27.
Yet the panel in the Steve Cardiff house boasts an even higher R-value. It’s been padded with styrofoam and spray foam insulation bumping the R-value up to 45 – almost four times higher than standard insulation.
The concept of vacuum insulated panels has been around for almost 20 years, but they’ve only taken off in the last five years. The ones used in the tiny house were donated to CCI three years ago by Panasonic but sat mostly unused aside from an install on a demonstration greenhouse at Yukon College.
When Blood Ties Four Directions, the non-profit group behind the house, approached the CCI for help, it was a perfect opportunity to contribute to a good project and demonstrate the effectiveness of these panels, says Mooney.
He’s hoping that vacuum-insulated panels will be used in the design of more low-cost houses in the Yukon. The up-front cost of these panels is more expensive than a standard sheet of insulation (they’re about $50 per panel). But the significant savings homeowners get on their energy bills will pay off over time, says Mooney.
One downside to the panels is that they start to lose their negative air pressure over time. The more air that leaks into the panel, the less effective it becomes.
Mooney would like to see renters and home-owners being able to suck-up any excess air with a simple blast from their home vacuum cleaner. A valve attached to a wall of panels could tell homeowners when the negative pressure is getting low. At the moment this technology doesn’t exist, but Mooney is hoping that CCI will be able to help develop it.
Installing the panels can also be a bit tricky. The contractor working on the Steve Cardiff house tried cutting the panels to fit the design of the home until he realized that he had rendered the panel completely useless. “If you cut the panel you let all the magic out,” says Mooney.
Even scratching the panel too deeply with your fingernail can damage the vacuum seal. That’s why panels are inserted about three inches away from the interior of a wall to avoid punctures from any nails or tacks.
The Yukon government’s Energy Solutions Centre worked on the project with CCI. They’ll be monitoring the effectiveness of the panels over the next year with the help of a heat sensor. The centre is planning to use the panels in other test projects, says communications coordinator Brigitte Parker.
If the panels are deemed a success they’ll be incorporated into more government-designed buildings. Yukon Housing, for instance, is looking at building small, cost-effective homes for the elderly in communities around the Yukon, says Mooney. Vacuum-insulated panels would work well in the design of these homes, he says.
It’s a way in which science can help solve practical issues facing the Yukon.
“The reason we first got involved with the tiny house project is because of the housing crisis and the need for lower cost housing in the Yukon,” says Mooney. “That little Steve Cardiff house now has the insulation equivalent to a SuperGreen home.”
This column is coordinated by the Yukon Research Centre at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at www.taiga.net/yourYukon