I'm ignoring many factors for the sake of being able to answer. There are some kinds of heating, especially using burning fuels that are nearly 100% efficient, but we don't know why it needs to get to that temperature, or how long it needs to stay that hot - so even if the transfer of heat is 100% efficient, this computation may underestimate the actual needs.

[–] platypus_plumba@lemmy.world 1 points 10 months ago* (last edited 10 months ago)

Ah, alright, I was feeling dumb because the formulas made no sense to me but it is just a model providing a practical approximation. Thanks!