January 2023 marks the second full year in our house at White Tree Farm. I’ve taken the opportunity to summarize the energy use for 2022 like I did for 2021.
To start, here’s the cooling and heating degree days per month for 2021 and 2022:
Like 2021, I continue to use 11 degrees C as the Heating Degree Days baseline and 22 degrees C for the Cooling Degree Days baseline. 2022 was definitely colder (HDD 2254 ) compared to 2021 (HDD 1980) with almost all of the difference occurring in January 2022. The summer months were about the same (CDD 138 for 2021 versus CDD 140 for 2022).
Here’s our total monthly energy usage for 2021 and 2022:
One major difference in 2022 was to reduce the use of the radiant heating in the shoulder months (April, May, October, November) by using the heat pump. This switched us away from propane and onto electricity for heating. In general, the heat pump worked well in this service. Because it does not heat the ground floor concrete slab to the same degree as the radiant heating, we definitely saved energy during these times:
Energy Base Loads
Like 2021, I was able to compute the base load for propane and electricity. In 2022, I got 18.1 kWh/d and 31.3 kWh/d respectively which were both down slightly compared to 2021.
Annual Heating and Cooling Energy Demands
I could now sum up our annual heating (14,844 kWh) and cooling demand (997 kWh) for 2022:
|Passivhaus Standard||PHI Low Energy Building Standard||The Birches @ WTF in 2022|
|Heating||15 kWh/m2/a||30 kWh/m2/a||42.8 kWh/m2/a|
|Cooling||15 kWh/m2/a||15 kWh/m2/a||4.0 kWh/m2/a|
The heating demand is up 5.9% from 2021 but the Heating Degree Days rose 13.9% for the same period. The cooling demand is in line with the 2021 numbers.
I continue to be pleased with the performance of the house. Using the heat pump system in the shoulder months has saved some energy over the radiant heating system. We hope to install a solar energy system on our workshop which could make the use of the heat pump even more economical.