Observations (Part 02)


Mill Creek NetZero Home, December 15, 2009, 14:00.

As we approach the winter solstice and the three-month anniversary of our moving in, we continue to learn about our new house. These observations are mostly qualitative, because we don’t have the rest of our solar modules up, and we haven’t set up monitoring equipment yet. We are tentatively planning to remove the door of our wood stove on July 1st, 2010  and then monitor the house’s energy use for a year.

  • we’ve been burning more wood that I thought we would (remember, we believe the house to require net zero energy without wood heat). When it’s minus 25 out (or minus 46), we have a fire for about four hours in the evening. Our electric baseboard heaters are set to 15 degrees overnight, (That’s not as uncomfortable as it sounds. It feels like 17 degrees did in our old house; chilly but fine for sleeping) and when we get up in the morning we start a fire right away to warm up the house. We can easily burn three armfuls of 16” long two-by-fours in a 24 hour period.
  • The house requires zero added heat when it’s sunny, no matter the temperature. We’ve sat comfortably at noon on a –28 degree day without the heat on.
  • The solar PV modules and hot water collectors get covered with snow. The movable solar awnings that we’ll be adding will solve that problem for two thirds of our modules. Even for the fixed collectors and modules though, the snow falls and melts off at the first sign of a warmish sunny day. Here is the house today:


Mill Creek NetZero Home, December 17, 2009, 14:50.

  • At this time of year we only get 4-5 hours of heat-giving sunlight per day. The first warm rays of sunshine enter the house at 9:30ish, and by three o’clock the lower windows are already mostly shaded by the garage and the trees across the alley (see above picture). The upper windows are shaded an hour later.
  • We fired up our solar hot water system sometime in cloudy October. It heated up to a high of 41 degrees C by November 18, down to 32 degrees on November 29, and 22 degrees today. Even at 22 (in a basement that’s only about 10 degrees right now) it is contributing to our hot water as the electric hot water tank heats it to 50 degrees.
  • Our total utility bill was $64 in November, exclusive of water (they’re not metering it yet). That was entirely made up of fixed charges for garbage pickup and grid connectivity.

Merry Christmas everyone!

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Hi Conrad

We moved into our house on December 11th, just in time for the cold snap. Since it's only been a week we're just getting to know the place. Like you we have noticed that because of the relatively "warm" exterior walls we can have the thermostat set at 19 C during the day and still be comfortable. Haven't had much solar gain yet and won't get as much as your place due to less south glazing and more shading. We did have some frosting on most of our windows last weekend. I'm hoping this is due to higher than normal humidity levels due to fresh paint etc. We have the same HRV as you do, selected for the same reasons. I still haven't figured out what the optimum settings are yet. During the cold snap I ended up running it on level 5 to try to bring down the humidity and did notice that it ran in defrost mode quite often. Prior to turning it up to level 5 I attempted to use the built-in humidity control. The setting on the control did not seem to corrispond to the humidity levels in the house so I just turned it up to level 5 in hopes of reducing the frosting. It sure frosted up the outside of the house and fence near the exhaust! I look forward to hearing more of your observations.

Merry Christmas

Hi Conrad
Just curious to know how your home is handling all this wonderful October sun and warm outdoor temps...Are you finding that it is overheating? Are you having to dump heat by opening windows??


It's been brilliant actually. I'll write more when time permits, but we're very happy with the lack of overheating.

We do open the windows on sunny days when we are sitting near them, and the cooling effect is nearly immediate and quite pleasant. In the evenings I've been opening our bedroom window two hours before bedtime and the room is cool to sleep in.

Overall, the passive solar aspect of this house has met and exceeded our expectations in every aspect.


That is great to hear! I was wondering if the thermal mass that you added was enough to counter the heat gain from those very large windows. I look forward to future updates.


Hi There,

What a wonderful site and a fantastic house. We want to build just West of Edmonton and are having trouble finding someone with knowledge of passive solar and super insulated building practices. Any reccomendations? I read tap the sun and know there is software available - looking for someone to guide us a little to build our dream house on a budget.


I'm currently building the Belgravia NetZero house. I've been thinking about how to respond to your request but I'm constantly coming up with more to say. I'd be willing to give you a tour of my house and an hour or two of my time to discuss my thoughts on building a state-of-the-art house. If you're interested, contact me at t6g0l9@lycos.com so we can arrange a time.


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