Category Archives: data

Preliminary winter performance data

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:

  1. We were only half-moved in for most of November – we started using the kitchen sometime in the second week.
  2. 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.
  3. 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.
  4. 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.
  5. However, that installation coincided with a serious cold spell where external temperatures dropped to -25ºC or lower.
  6. 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.
  7. 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.
  8. 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.

Heating and low temperature performance

We finally had the little Thermolec 2kW heating element installed in the HRV intake last week, just in time for a cold snap. This element is a bit like a toaster and heats the air coming into the HRV manifold that distributes heat around the house. It is controlled via a thermostat, which is downstairs and not too far away from the kitchen so we are aware that it’s likely to be a bit warmer there than elsewhere, so we keep it at 20ºC, knowing that this is likely to mean 18ºC on average around the rest of the house.

All the other heat comes from passive solar, i.e. the south-side windows, but it’s been quite dull recently, so that has not been such a big factor. In addition we’ve been having further problems with the Motura sliding door. We already had to have it taken off and some new sealing rubber put on, but it’s still not tight. This was not apparent in the recent blower-door tests, we think, because when you pressurize the air inside the house, the sliding door would have been pushed outwards, against the seals. However, at other times, this is not the case, and the higher we have the HRV settings the looser it gets. Compared to most houses, it’s not at all bad, but there is still an appreciable draft around the edges of the sliding door. We have contacted the supplier and await some advice. We might just push some of the left-over rubber gasket from the CLT construction into the edges and tape them up, just for the winter.

We are recording temperature levels a project at Algonquin College, but that data won’t be available until it’s downloaded from the recorders. In the meantime, we are just keeping an eye on performance using simple thermometers, particularly when it’s cold outside. And last night, it was very cold outside. When we got up, the external thermometer was reading -15ºC, so it could have been even colder during the night, and the winds have been fierce here, so the effective temperature would have been around -25ºC.  When we got up the temperature inside was 14ºC upstairs and 16ºC downstairs. With some sunlight in the morning and a few hours of an additional 1kW heater, this was soon up to 19ºC downstairs and 18ºC upstairs, and it has pretty much stayed that way since, as the winds blow around the house. This is pretty good. But we shouldn’t need the additional heater, and until we resolve the problem with the Motura door, one way or another, we will not be able to get the more consistently warm temperature levels we would like. It’s certainly not cold – it’s very comfortable – but the house is not yet operating at its optimum.

Roofing, Painting and Data Logging

The roofers were back today and finished off the porch roof. However, they will have to come back again to change a couple of things, most importantly to change the way the downspouts from the roof are configured, so that they go directly into the cistern rather than send the water onto the porch roof. It rained a lot overnight and this morning and it was clear from watching that the speed of the water coming down onto the porch roof was such that it just shot over the top of the porch eavestroughs rather than pouring into it. We are also going to have them put in gutter guards to stop the system getting clogged up with leaves and so on.

Also today, Anthony Mach of Mach Design, who was the architect of the Manitou Hills almost-passive house build detailed on the Sunshine Saved blog, came over. He’s doing research work as part of a course at Algonquin College that he’s taking, and he installed data loggers upstairs and downstairs in our place that will record temperature and humidity over the next three months. It was nice to chat with Anthony about common interests and passive house problems.

Finally this week, we’ve started painting doors. It’s one of the areas of the construction where there will be colour. During the process, we’ve been changing our original ideas, which were to have almost every door as a different colour, to being a bit more conventional, because it just didn’t work. The apple green that we’d had mixed for the toilet doors looks a bit too neon in reality and while it’s a perfectly fine colour in itself, doesn’t work against the background colour of the raw spruce or the colour of other nearby doors. So, we’re going to repaint the one upstairs bathroom door with the same colour as the bathroom door and wall (Homestead House’s ‘Laurentian’), and downstairs we’ll use the same Benjamin Moore Nature ‘Mandarin Orange’ – what the Japanese would call みかんいろ – as we have used in the main room.

For the one doorway that doesn’t have a door, the one between the kitchen and pantry, we have put up a Japanese noren, a split curtain. This one is a rather beautiful hand-dyed genuine indigo noren from Tokushima prefecture on the island of Shikoku.