A home heated by sand? It’s just one of the enticing technologies being tested at the Urbandale Centre for Home Energy Research, a glossy name for a very ordinary-looking home perched on a sunny rise at the north end of Carleton University’s campus.
Visible from Bronson Avenue, the recently completed two-storey, wood-clad house is the result of a long-running collaboration between Urbandale Construction and Carleton University with an eye to enhancing energy efficiency, maximizing solar energy and reducing greenhouse gas emissions.
Ian Beausoleil-Morrison, a professor in Carleton’s department of mechanical and aerospace engineering, came up with the idea for the research facility. Urbandale, a leader in green building, kicked in $200,000 and helped with design and construction. Fourth-year Carleton engineering students also contributed energy-generating and other ideas, and the Ontario Research Fund and the Canada Foundation for Innovation helped fund the $1.5 million project.
The 1,600-square-foot house — which inside is left at the drywall stage but divvied up into a main living area, three bedrooms, and a basement bristling with pipes and instrumentation and hulking mechanical systems — will officially open in 2016.
Back to the sand. Saturated with water to enhance heat retention capacity, the sand is in a heavily insulated, six-by-six-by-three-metre box buried beside the house. A rooftop solar array heats the soggy sand during the summer, and in the winter the stored heat warms both the house via a radiant floor system and services the domestic water supply.
“We calculate 90 per cent of space and hot-water heating needs will be met with the system,” says Beausoleil-Morrison. “We wanted to make (the box) a practical size,” he adds, the kind of thing that could conceivably fit in a suburban backyard.
We calculate 90 per cent of space and hot-water heating needs will be met with the system
Beausoleil-Morrison and company are also testing other heating systems, including a cold-climate air-source heat pump from Ecologix. Air-source systems, which use refrigeration technology to extract heat from outside air to warm buildings, can deliver one-and-a-half to three times more heat energy to a home than the electrical energy they consume, according to the U.S. Department of Energy.
Problem is, they’re usually effective only to around -15 C. The set-up at Carleton pre-warms the air by passing it through buried stone (it’s warmer below grade than above) before it enters the system. That should make the heat pump effective to about -30 C, says Beausoleil-Morrison.
“We don’t know if they’re going to work,” he says disarmingly of the multiple technologies in the home. “But it’s low-risk because there’s no one living here … We’ve used lots of assumptions and models, and we’ll find out if they all work when we do the testing.”
Initial testing of some mechanical systems has already begun.
The house also employs more standard energy-efficiency strategies. For example, windows on the heavily glazed south side will help provide winter heat via solar gain. But because they are triple-paned and argon-filled with double low-E coatings, heat loss at night will be minimized.
As well, one of Beausoleil-Morrison’s students has developed software to control south-side window blinds based on how the house will respond to forecasted weather. When the summer sun threatens to overheat the home, the blinds roll down.
To reduce heat loss, there are no windows on the north side. However, there are removable panels in the cladding to allow monitoring of building performance or changes to technology.
Urbandale has also integrated some of its standard specifications into the design. To help keep basements in its homes dry and mould-free, for instance, the company uses a “proud” foundation that’s heavily insulated from the outside to reduce moisture penetration. That design has been incorporated into the research facility.
Despite major advances in air tightness and the efficiency of residential mechanical systems, there’s still lots of work to do be done in exploiting solar energy to displace natural gas and electricity, says Beausoleil-Morrison. That’s where much of the focus of this research facility lies, and he says that means the advanced technology being investigated needs to have potential application to the real world.
“Everything we’re looking at, we ask, ‘Is it practical?’ It can’t be too esoteric.”