Harmony House generates as much energy as it consumes
Insulation is at the core of efficiency that helps make Burnaby house 'net zero'
On a cold January day, frost crunched beneath boots on the walk up to the front door of the newly-constructed home in Burnaby. How could this house, in the middle of winter, be producing as much energy as it consumes?
The answer is simpler than you might expect: insulation.
But insulation is only one part of what makes Harmony House such an interesting — and efficient — residence.
Creating a net-zero home
Harmony House is the name given to Les and Linda Moncrieff's home, a replacement for their previous residence that was destroyed in a fire. Just off Boundary Road, it's nestled on a South Burnaby hillside with a view that looks out over the Fraser River.
Chris Mattock of Habitat Design, who has been designing energy-efficient homes for 30 years, won a Canadian Mortgage and Housing (CMHC) competition to design Harmony. Insightful Healthy Homes owner Arthur Lo was the builder of the project.
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.
How Harmony is heated
Thin panels in walls use a vacuum space to insulate, to a stunning R38
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.
"When you build a super-efficient house," says Gary, "the question of how you heat it becomes less and less important."
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. (Typical air-sourced heat pumps will only operate to minus 7 degrees C.)
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.
Fresh air matters
Heat recovery ventilation system removes moisture from kitchens and other rooms
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.
But it doesn't stop there. The ventilation system is also efficient. 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.
Lighting up the space
On a grey, cloudy day, Harmony is well lit with natural light, thanks to the many south-facing windows. In fact when there is enough sunlight in the living room, daylight controls will turn out the artificial lights.
And the house was constructed with numerous dimmable LED "pot" lights embedded in the ceilings of all the rooms which provide gentle, diffuse light throughout the space. The rest of the lights are either compact- or linear fluorescent.
The lights are all controlled by wireless switches, too, which can be moved anywhere it's convenient to place them.
And the ingenious switches, provided by Squamish-based Echoflex are battery-free. All the energy required to send the wireless signal is generated by the act of pushing the switch.
What you can do in your home
Many of the technologies and appliances that make Harmony House so efficient were donated by the manufacturers who wanted to see their equipment in action.
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."
In the meantime, here are some simple, less costly things you can do to make your home more efficient:
- Switch to energy-efficient lighting
- Turn lights off when you leave the room
- Plug those drafty cracks and holes
- Reduce the amount of power your electronic devices use when in stand-by mode
What can be learned from Harmony House
BC Hydro is using Harmony as a research project of sorts. They've set up a Home Energy Display System, an end-use monitoring system, so that electricity use can be tracked on a minute by minute basis.
Gary grins as he shows how the residents of the house can view the information on televisions in the house, or even on a tablet computer. It's a glimpse, he tells me, into what the future might be for energy management in the home.
Being able to see how much energy appliances and electrical devices need can be quite illuminating.
"People can't make good decisions without good information," says Gary.