Time to do the math

Should we care whether Y Foel uses 14, 15 or 16 kWh/(m²yr) ?

Well I do. It matters a great deal to me. Imagine spending 7 years planning and building your own house; putting your faith in a design standard you'd never heard of; committing all your savings; riding the self-build emotional rollercoaster, and then being the first in the UK to achieve certification.

It would not be the end of the world if we used more that 15 kWh/(m²yr), but it really would make me feel a whole lot better if we were at least very close; particularly in a year with much lower monthly temperatures than used for our PHPP climate model.

PHPP certification is based on science and practical experience, but it provides a prediction of space heating requirements, not a measurement.

I hope we can provide further encouragement to UK builders and policy makers by proving the prediction in practice.

So what does the math say right now?

With 52 days remaining we have used 1,025 kWh for space heating.
A total of 1,493 kWh after one year would place us at exactly 15 kWh/(m²yr).
This means we have another 468 kWh for the next 52 days, and the indoor temperature must remain at or above 20°C.

I will be providing daily space heating numbers to the monitoring graphs in the next few days.


Posted By: MarkTiramani

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