A component that calculates the thermal mass.
It could be used to calculate the heat of a room with different input : solar light, added heating …
It could also be used to transform solar electricity production in all the thermal systems : solar thermal water heating, passive house temperature prediction…
The decay of temperature over time with the delta from outside temperature.
I think you are more or less requesting a sort of ‘modelling’ integration? I’ve thought about such an idea in the past, but an issue that I have is that it doesn’t really have a ‘state’ per se, we are really trying to use the data we get from home assistant for something else. Obviously you would then want to use your estimate of the parameters next in automations of course, but I’m unsure if an ‘integration’ is a good fit.
Right now I find data science using my home assistant data a bit of a struggle at least, so something to help with that would be very nice! I believe there’s a lot of value to be gained from it, like predicting heat loss as in your request (and I assume as a result a much better heating).