January 2025 marks the fourth full year in our house at White Tree Farm. I’ve taken the opportunity to summarize the energy use for 2024 like I did for 2023, 2022 and 2021.
To start, here’s the cooling and heating degree days per month for all four years:
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I continue to use 11 degrees C as the Heating Degree Days baseline and 22 degrees C for the Cooling Degree Days baseline. The HDD for 2024 was the lowest for us yet (1749) while CDD was about average (128).
Here’s our total monthly energy usage :
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In 2024, we continued to use the heat pump as the primary source for heating and it once again proved to be a big energy saver.
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Energy Base Loads
For 2024, the base load for propane and electricity were calculated to be 20.7 kWh/d and 30.8 kWh/d respectively. These are in line with the previous years.
Annual Heating and Cooling Energy Demands
I could now sum up our annual heating and cooling usage for 2024 which were 6045 kWh and 1953 kWh respectively,
| Passivhaus Standard | PHI Low Energy Building Standard | The Birches @ WTF in 2024 | |
|---|---|---|---|
| Heating | 15 kWh/m2/a | 30 kWh/m2/a | 17.4 kWh/m2/a |
| Cooling | 15 kWh/m2/a | 15 kWh/m2/a | 5.7 kWh/m2/a |
Minimizing the use of the radiant floor heating has significantly improved the heating numbers for the house to the point that it passes the PHI Low Energy Building Standard. The cooling demand is in line with the 2021, 2022 and 2023 numbers and well below the PHI Low Energy Building Standard.