Russell Richman, a professor in the Department of Architectural Science at Ryerson University, is the co-principal investigator of a research project exploring the practicality of what is called nested thermal envelope design. Space heating is the largest single contributor to residential energy use in Canada at 60 percent of the total. Minimizing envelope heat losses is one approach to reducing this percentage.

The nested thermal envelope design has two key components. First, the home must be divided into two different zones: the perimeter and the core. The core is the home’s main living area, for example, the kitchen, the living room, and bedrooms. The perimeter is those less often used rooms, such as a formal dining room, sunrooms, and secondary bathrooms. Secondly, the home must have a small heating unit that cycles heat from the perimeter into the core during the winter season. In this case, a heat pump funnels heat lost to the perimeter back into the core of the home.

This nested thermal envelope design was originally conceived by Richman and his colleague, University of Toronto professor Kim Pressnail, following a discussion between the pair on the heat loss they were experiencing in their own homes. After considering the practicality of simply living in fewer rooms, the researchers experimented with the practice of living in a smaller space while also recycling heat from within their homes. Along with Ph.D. candidate Ekaterina Tzekova, also from the University of Toronto, the team has been evaluating variations on nested thermal envelope designs since 2007.

After drafting the original design, the research team tested it using the EnergyPlus building energy simulation program. Calculations showed possible energy savings of up to 80 percent.

This winter, the researchers are moving into the next stage of the project. The nested thermal envelope design will be implemented in a home in downtown Toronto. The team will elect test subjects to live in the home, beginning with a student and, later on, the home will become a residence for visiting professors. The research team will track behavior patterns and get feedback from the occupants themselves.

“The question is, is it worth the additional effort of installing a heat pump? The heat pump needs to be servicing a lot of energy in order to validate this design,” said Richman. “There are so many research questions to be answered with the house. It’s always exciting to take theoretical research and turn it into practice.”

Richman and his colleagues hope to collect data from the home and its inhabitants over the next five years, after which time they will continue their research with a custom built home.

Publication date: 1/14/2013