We have had temperature and humidity data recorded in the house over the last 4 months as part of a project conducted by Anthony Mach, a passive house designer and Building Science research student at Algonquin College. The preliminary data is now available, courtesy of Anthony. What we have here is essentially the raw temperature and humidity records in two locations: one in the middle of the open-plan downstairs space (1st Floor), and the other upstairs on the landing (2nd Floor). There is a lot of analysis to be done with this data combined with other data on external temperatures, energy use and so on.
A few things to note when looking at these charts:
- We were only half-moved in for most of November – we started using the kitchen sometime in the second week.
- When we moved in (around the 21st November), the HRV (which actually turned out to have an ERV core – for more on the differences, see here) had still not been properly balanced and we were still only using the system on its lowest setting.
- After the HRV had been balanced properly on the 4th December, we started using it on the middle setting, with boosts after baths and during cooking.
- We only had the 2kW Thermolec heating element, that works with the HRV, installed on December 14th. Up until that point we had only been using a single 1kW space heater. If it was cloudy in the morning after this point we used both, but if it was sunny we didn’t need the later.
- However, that installation coincided with a serious cold spell where external temperatures dropped to -25ºC or lower.
- We were away from the 20th to the 30th of December, and had the HRV just ticking over, which means that the house would have had almost no internal heating. You can see the drop, but what’s remarkable is that the place still never got below 13ºC.
- Once everything was back to normal and functioning properly, from early January, the temperatures in the house were generally between 17ºC (average night-time low) and 19ºC (average day time high) upstairs, with the extremes being 15.5ºC and 21ºC; and 18ºC (average night-time low) and 20.5ºC (average day time high) upstairs, with extremes of 16.5ºC and 22ºC. The difference is probably explained by a combination of the use of the extra heating downstairs, the passive solar effect from the larger windows, and generally that there is more activity downstairs for more of the time.
- The humidity has generally been where you’d want it, between 40 and 50%, gradually drying out as winter goes on. Our HRV having an ERV core helps in stopping the place getting too dry.
We’ve not been posting recently because not much is happening. We’ve had and passed the electrical inspection, which means we can actually start to put in the light fittings we intend to live with (which are mainly European and Japanese and while perfectly safe, have not been submitted to Canadian inspection). Chris and Anne from New Leaf Custom Homes came round to discuss the few small things we need to do to get through the final inspection and get our official occupancy permit, which should get done over the next couple of weeks. Beyond that, we don’t have the money at this point to do anything else for a few months. So, the Japanese room, built-in shelving will have to wait, as will the solar array and home battery system.
We’ve had a few interesting and critical comments on aspects of the design from the edited reposts of earlier blog entries that are being published on the excellent Green Building Advisor site, and I’ve responded to those in the site, but the simple observable truth is that the house works. We’ve been in it since December now and even though this has been a grayer and cloudier winter than usual, which means the solar gain is less than normal, the house has still been maintaining an even interior temperature of between about 15ºC (nighttime low) and 21ºC (daytime high) without the wood or pellet stove that so many people insisted that we would need. Rainwater / snow-melt harvesting has also provided for all our water needs without any sign of getting low, although this winter we may have benefitted from the unusually uneven temperatures. Short version: whatever, we could have done differently, and indeed would do differently were we starting again, it’s all good. We already published some reflections on why we did things the way we did, last year, but I will do a more detailed post on exactly what we would change were we starting again, because that’s really what everyone else who might be considering this kind of house wants to know…
Now here are some more pictures…