After having a series of energy efficiency improvements done to our home in Charlottetown, we received the following rating from an EnerGuide efficiency evaluation:
Our “before” audit showed us using 85GJ/year and our “after” audit has us down to 51 GJ/year. We had cold climate air source heat pumps added (like, a lot of them) and spray-foam insulation added to accessible portions of our basement foundation walls (including sealing some glaring air gaps out into an unconditioned garage).
The house already had a ~16kw solar panel system when we moved in last year, so the solar is incorporated into the before and after evaluations.
These evaluations are approximate. There’s no measure how how much energy I’m actually using. They do a blower-door test to measure for air-tightness (our “air leakage rate at 50 pascals” is 3.89 air changes/hour – down from 5.7 before our recent improvements). Beyond that, the values are calculated based on number and type of windows, house size, and a bunch of other static measurements.
So, these values could be better if I keep the house freezing all winter, or much worse when the kids leave the door half open in the middle of winter.
I do like that the rating from EnerGuide Canada includes this note:
One gigajoule (GJ) equals the energy from two BBQ propane tanks
Maybe a BBQ propane tank is the “football field” or “Olympic-sized pool” (!?) measure for energy. Note that this is just for comparison. We’re not actually powering our home with primarily with propane.
Knowing our house could be using around 100 BBQ propane tanks of energy per year sounds pretty low, and way too high at the same time.
We had our audit done in the fall, and our “before” is 261 GJ. We chose to look at this as a “nowhere to go but better” rating. The house is 197 years old, no insulation in the walls, no basement insulation, very old windows. I’m hopeful we can get into sub-100 GJ territory.
Our place is fairly large to accommodate my dozens of children. I wasn’t really sure how our 51GJ/y number compared to others. The solar panels must be carrying a lot of the load for us, and we’re rarely burning oil any more. There’s more to do!