Thornleigh Passive House

Another month in the house, and we are getting a lot better with managing the night ventilation... The 4% of hours that were less than 20 °C were all associated with excessive cooling of the house over night prior to hot days. In the house the highest hourly temperature (26.2 °C) was recorded in the northwest bedroom, and the lowest hourly temperature (18.3 °C) was recorded in the Study. Outside the highest hourly temperature was 38.7 °C, and the lowest hourly temperature was 7.9 °C. At no point in November was the A/C used. Starting on November 20th we started logging the HRV system in collaboration with Zehnder (the maker of our Zehnder ComfoAir Q 350) and FanTech (the Australian supplier of the unit). Sydney is a borderline situation where it is not clear which type of system is better. So they are interested in comparing Heat Recovery Ventilation (HRV, only heat is recovered) with Energy Recovery ventilation (ERV, where heat and moisture are both recovered). The unit used for

We had ~49 people come through the house for one of the International Passive House open days of 2019. As the event is not as widely publicised as Sustainable house day when we had more than 200 people through. The visitors who came through for this open house tended to already know a fair bit about passive houses (with many dragging along family members who they were working to convince of the merits of passive house living). Lots of the visitors were already planning or working on projects that were including passive house principles.

Link to a plot of the WirelessTag data from sensors relating the the performance of the HRV (heat recovery ventilation) system... note that between 1800 on November 1st and 0600 on November 2nd the sensors were being cross calibrated and were not where they are supposed to be.

Link to plots of the WirelessTag sensors data associated with the water wall versus adjacent ambient air temperature ... note that between 1800 on November 1st and 0600 on November 2nd the sensors were being cross calibrated and were not in the water tanks. The water tank sensors in situ:

I now have many temperature sensors around the house... and it is important that they are comparable. So here I outline the steps I have taken to ensure that the sensors yield comparable data. While I have attempted to cross calibrate my temperature readings I have not yet attempted to cross calibrate my humidity readings (which I really should do, and I will do when time allows). Calibration 1: On the 21st of September I put all the sensors I had on the kitchen bench and used the calibration options within the various software packages to adjust all the sensors to a single value which seemed to be the central tendency of all the sensors. Calibration 2: Last night I did the same thing, but with some new sensors and I did not bring in the sensors from outside. November 1 calibration Sensor Calibrated (°C) Raw reading (°C) δ °C Clerestory 23.60 24.09 -0.49 Mufraj (NE) 24.60 25.33 -0.73 Bedroom Southeast 24.60 24.87 -0.27 Bedroom Northwest 24.70 24.98 -0.28 Bathroom Exhaus

The sensors have now been set up for over a month (since the 22nd of September), so this "October temperature summary" includes all the data between September 23rd and October 31. This month we were still learning how to best manage the house, with some operator oversights that could have improved these numbers a bit (i.e., remembering to lower the blind, opening windows for night ventilation, and picking the best HRV settings). But I think the numbers still look good. At no point during the period covered by these data was any additional heating or air-condition used. Methods: I have taken the 5 minutely data from the wirelessTag sensors and calculated the median temperature of each sensor for each hour and determined the proportion of hours falling inside of the 20 - 25 °C target temperature (using the R functions 'aggregate' and 'hist'). Inside is the data from the wirelessTag sensors in the Kitchen, Mufraj, Master and centre bedrooms. Outside is the dat

One of the keys to passive house is air tightness and mechanical heat recovery ventilation... which is great most of the time time. But during hot days and cool nights it is often beneficial to get as much night time cooling (i.e., ventilation) as possible - which means opening the windows. In our passive house the primary thermal mass is the water wall, and the house is designed to allow for efficient night ventilation of the house and water wall by opening two panels of the big north facing window near the water wall and the clerestory windows at the top of house. This creates a ' stack effect ' with the hot air rising out the top of the house helping to pull cool air in the house at the bottom... across the water tanks in the process. Last night was the first time we opened the windows to allow this night time cooling to happen (as today's weather was forecast to be very warm we wanted to cool down the house as much as possible before hand). While I'll work on a

The things one learns about ventilation... Our heat recovery system is set to by default to replace 1/3 of the house air volume every hour, and we have nifty little Netatmo sensors that measure carbon dioxide (amongst other things). I say 33% of the volume by default because the bathroom and kitchen contain booster switches that increase the replacement to 50% for 30 minutes - designed to clear the effects of cooking, showering, and other such activities.  Here I've attached a "normal day" from last week. It is fairly clear when the parents leave their bedroom to start their day, when we get home, and when we go to bed. In comparison our old house, had no mechanical ventilation but did leak like a sieve. The carbon dioxide levels in the living room of the old house would routinely get above 2000ppm, and quite often didn't quite get back to 400ppm before we came home from work/school unless the windows were left open. In the new house carbon dioxide levels

The first month of temperature data. It took several weeks to get the NBN connected, so only a week or so with a fully array of sensors hooked up. The temperature data are not all of equal quality...  These data are from wireless tags ( WirelessTagWebsite ,  WirelessTag Data ). The CubbyHouse sensors (2) are outside temperature, whereas the rest of the sensors are in various rooms of the house. The house temperature is maintained with a mechanical HRV system, but no active heating or cooling has been used this month. Overnight on the 22nd all the sensors were in the same location (kitchen counter) so that they could all be synchronised / calibrated against each other.

The garden between the driveway and the front fence in coming together with drip irrigation and some plants added. Callistemon viminalis Captain Cook (x4) [ ANPS ] Callistemon pearsonii (x4) [ ANPS ] Hardenbergia violacea (x4) [ ANPS ]

A successful sustainable house day open house with 174 adults and 50 children coming through Thornleigh Passive House. Also the Certified Passive House plaque was put up.

Three cubic meters of woodchips (delivered and spread in the front of the house). Four native trees planted to meet council requirements. The Acacia should just hit the required 6m height, so they are on the north side where they should not shade the solar panels. The other two will get much taller, so they are on the southern / western side where they should not shade the solar panels too much. Acacia floribunda  (x2) [ wikipedia ] Elaeocarpus reticulatus  [ ANPS ] Tristaniopsis laurina  [ ANPS ]

Many blogs start... fewer continue. The aspirations here are quite simple: to provide a small window into life in Sydney's first certified passive house and some of the geeky the operational information. The goal is a monthly or at least quarterly updates on house the house is performing, along with some random commentary about the challenges, opportunities faced, and problems solved.

We've moved in...

The fifth estate on the first certified passive hosues in greater Sydney.