Canadians pride themselves on being hardy—and especially on being able to withstand weather extremes. We compare notes on the depth of our snowfalls, then go out and play hockey when it's -20 degrees.
The homes we live in aren't quite that immune to the cold though.
According to the National Research Council of Canada, up to 60 per cent of our residential energy use goes to heating our homes—a number that is often so high because much of the heat that's generated rapidly escapes. In an effort to retain more of that heat, and cut energy use, some Toronto researchers and architects are now piloting a nested thermal envelope home design: essentially creating a home within your home, to facilitate heat retention.
Ryerson professor Russell Richman is the co-principal investigator exploring the design. He's working with a colleague from the University of Toronto, Kim Pressnail, as well architecture firm ERA. The idea arose soon after Richman had a baby, he says, and his family had to go from a cooler house to one that was constantly heated to keep the baby comfortable. This got him wondering "Why can't I warm just one little zone?" So that's what Richman then proceeded to do, by installing a space heater. But it also got him thinking about how that effect could be recreated in a larger living space.
The nested design works by creating two zones within a home: a main, fully heated zone at the centre of your house where you do most of your living, and a perimeter buffer zone, which is kept at five degrees. The temperature difference between the zones reduces heat loss off the bat, and then a heat pump installed between the core and the perimeter pumps heat back into the central core of the house before it escapes entirely.
Richman and his colleagues are piloting their concept at a house owned by the University of Toronto, which will provide them with some information about the viability of the nested design as a retrofit for existing homes. That's the harder case. Future investigations will look at how the zone model can be incorporated into new construction from the outset.
Writer: Hamutal Dotan
Source: Russell Richman, Professor of Architectural Science, Ryerson University