2026 May

May was cooler and very wet. Outside temperatures ranged from 7 to 26 °C (median temperature 16 °C), while inside we were a comfortable 19 to 24 °C (median 22 °C). The HRV was mostly between seasons but flirting with the heating season, so the split system mostly off or set to 21 °C heating. With the sun mostly hiding behind the rain clouds the rainwater tank is full, but the solar production was lower than typical.

Temperature from inside and outside the house as the percentage of hours in 0.5 °C bins. I've scaled the temperature in hope that I will be able to use the temperature range for all months. We have made a decision to keep the house above the WHO recommended 18 °C rather than the passive house standard of 20 °C.

Methods: I have taken the 5 minutely data from the wirelessTag sensors and calculated the median temperature 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 includes data from the wirelessTag sensors spread across nearly every room of the house. Outside is the data from the wirelessTag sensors outside near the cubby house. The water wall data are not included.

Energy production and consumption: 1. total daily consumption and solar production, 2. daily net energy production (energy produced - consumed), 3. energy independence (1 - (imported / consumed energy)), and 4. solar offset (energy produced / consumed).

Some notes about the energy plots... Currently the batteries are configured to maximise our cost savings, which means we import / export electricity to avoid imports during the peak demand period. The batteries will also top up from the grid when weather (including fire) warnings are issued to ensure that the batteries are full should the gird power go down.

Popular posts from this blog

Temperature (Out vs. Old vs. New)

Image
I have fielded more than a few questions about the temperature of our passive house versus the temperature of the house that we lived in prior (on the same lot).  So I've used the data I had on hand which is temperature (°C) recorded every 5 minutes over since October 2012. For the sake of consistency I am only using the NetAtmo sensors that I have had for that entire period. So I only have one outside sensor and one inside sensor located in the the respective living room. The outside sensor moved around a bit, but it should be good enough.  I've converted those measurements to hourly averages.  This ends up being ~ 66,955 hours to play with (52,232 hours from the original house, 14,723 hours from the passive house). I've left the rental house out of this comparison, but it was disturbing like the original house despite being ~ 20 years old. The key take-home messages: The passive house a much less variation in temperature than the original house (or outside).  ...
Read more

2025 June

Image
June was decidely wintery (median temperature 11 °C). Outside temperatures ranged from 2 to 21 °C, while inside we were a comfortable 19 to 23 °C. The HRV was in the heating season and the split system was set to heat to 20 °C. Now that we have solar house batteries we no longer need to schedule the split system to run during solar generation as we have done prevously. Temperature from inside and outside the house as the percentage of hours in 0.5 °C bins. I've scaled the temperature in hope that I will be able to use the temperature range for all months. Methods:  I have taken the 5 minutely data from the wirelessTag sensors and calculated the median temperature 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 includes data from the wirelessTag sensors spread across nearly every room of the house. Outside is the data from the wirelessTag sensors outs...
Read more

Carbon dioxide (Old vs. New)

Image
I one of the things I've noticed is the carbon dioxide levels in our passive house compared to our old house which had plenty of draughts but no ventilation aside from a bathroom exhaust fan.  So I've used the NetAtmo carbon dioxide data collected every 5 minutes since October 2012 to quantifiy the differences.  I only have a single sensor located in the respective living room of each house.  I averaged the raw measurements to get hourly averages.  Because I most interested in peak carbon dioxide - I've taken the maximum hourly average for each day. This ends up being 2,192 days from the original house, 615 days from the passive house. I've left the rental house out of this comparison, but it was disturbing like the original house despite being ~ 20 years old. By way of standards: 420ppm is typical CO2 level outside, less than ~ 1000ppm is considered to be good, levels greater than 2000ppm are often associated with headaches and drowsiness. The key take-home mes...
Read more