IPOD - June 2024

International Passivehaus Open Days - June 2024 edition. We were open and hosted 40-50 people (didn't get an accurate count). We met some lovely people and chatted passive houses.

Just because folks asked... a couple of graphs (using the same hourly data from the monthly summaries). An updated all available data (40,133 hours) histogram:

temperature histograms - inside & outside.

An important note on these data. More than half of the hours above 25 °C (546/1026) occurred in the first 6 months of living in the house, and all of the hours where the inside temperature above 27 °C were in the first 6 months living in the house when we were still determining the optimal HRV settings and how to manage the house temperature (learning that a passive house is designed for temperature inertia and benefits from a set and forget approach).

Looking at 37,258 hours between March 2020 - June 2024, the house is in the passive house target zone of 20 - 25 °C 95% of the time, and in our target range (18 - 12 °C) 99% of the time. The 18 °C lower temperature threshold is the World Health Organisation threshold temperature, relative to the passive house value of 20 °C. The World Health Organisation does not set an upper threshold whereas the passive house upper threshold is 25 °C. 


I regularly comment that 26 °C is a really nice temperature when I come in from an outside temperature of 40 °C... which begs the question about the relationship between indoor and outdoor temperature. In the graph below the diagonal line is represents the same temperature inside and outside... and you can clearly see that the indoor temperature and outdoor temperature are not along diagonal line. Most (95%) of the indoor temperature hours are in the 20 - 20 °C range regardless of the outdoor temperature. Four percent (4%) of the indoor hours are between 18 and 20 °C. Four of 37,258 (0.01%) are below 18 °C, and 1.3% of hours (491 of 37,258) had indoor temperatures above 25 °C. 

Those hot hours are -- as expected -- mainly during the summer (73%) and between 2 and 6 pm (62%).  Thinking in terms of days rather than hours, 106 of 1553 days had hot hours. Two thirds (64%) of those days had four or fewer hot hours.



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