Super-efficient home in Burnaby combines vacuum insulation, solar gain and air-source heat pump to achieve "net-zero" energy

Harmony House generates as much energy as it consumes

Insulation is at the core of efficiency that helps make Burnaby house 'net zero'. But insulation is only one part of what makes Harmony House such an interesting — and efficient — residence.

The two-storey, 4,700 square foot residence with a full basement and attached garage is part of the Equilibrium Sustainable Housing Demonstration Initiative, a CMHC program to encourage designers and builders to explore truly sustainable housing developments.
A net-zero energy home produces as much energy as it consumes, annually, through energy conservation strategies and the use of renewable energy technologies.
Additionally, the design team set the goal for the home to produce zero greenhouse gas emissions. This eliminated the possibility of using a combustion appliance for space or water heating so there's no gas line into the house at all.

Conducting a recent tour of Harmony was Gary Hamer, manager of technology and innovation with BC Hydro. He estimates that it will take 2,500 kWh per year to heat the residence, about a fifth of what it would be for a conventional home.

The first part of that solution is insulation. In all of the exterior walls of Harmony House are thin panels which use a vacuum space to insulate. They work because heat can't transfer across a vacuum. The vacuum panels also allow buildings to have superior insulation while maintaining conventional wall thickness. While a wall in standard house is built with an effective insulation rating of about R16, Harmony's effective wall rating is R38.

Triple-glazed windows also help keep the house warm. Even on this January day, from the inside of the house the windows don't feel cold. Nearly a quarter of the heat needed by the home will come from solar gain — that's heat from the sun — via windows on the south of the structure.

Additional heat comes from a very efficient air-source heat pump that cycles a refrigerant from outside and into the house. It's is so efficient that it can effectively pull heat out of the outside air at temperatures as low as -18 degrees Celsius. The same kind of heat pump is used to heat water. Gary says that being able to use one outside source, one piece of equipment, to heat both the space and the water is ideal in some circumstances.

But houses need ventilation, and Harmony House is nearly airtight.
So fresh air is brought into the building using a heat recovery ventilation (HRV) system. It exhausts stale air from rooms that could have moisture — bathrooms, kitchen and laundry rooms — and brings fresh air into the bedrooms and other living spaces. Rather than waste the energy used to heat the indoor air, the air leaving the house preheats the fresh outdoor air coming into the home. Around 80 percent of the heat is recovered.

Always being on the look out for better and more efficient ways of using electricity, Gary is excited about better ways of heating homes and water. He is currently studying the effectiveness of ductless heat pumps in a pilot on Vancouver Island.
"The pilot's goal is to measure the amount of energy that high-efficient ductless systems can "displace" from the less efficient electric baseboard heaters that currently heat these homes," he explains. "I believe that properly applied, efficient heat pumps hold much promise in saving energy and increasing occupant comfort. But like all good science, what equipment and when to use it must be determined first. That's where our pilot comes into it. And the data gather from the Harmony House will add to our knowledge."