Interesting. I was going to just put a pause on the accumulator at that point. I’ll ponder the consequences.
I’m getting a “catch up” at the end of my hot water run because I take the really hot water in the pipes and pump it round the radiators. It’s only a couple of minutes, but it seems to be working (well, so far in the Winter anyway!)
With your algorithm it gives you a good behaviour even if the hot water runs for a longer time for some reason then the accumulator will keep driving down and trigger the space heating soon after. By using the “difference” from before the hot water came on they are essentially extrapolating the behaviour over the time of the hot water production so it doesn’t get confused by the exciting flow temp. It’s a good strategy which is working nicely because the changes that would disrupt the extrapolation, such as outdoor temp changes, won’t be very large over a 10 or even 30 minute period.
Good, now your mapping is heading in the right direction.
You are right that there are two parameters: firstly the slope, currently 0.67 flow degrees per outside degree. Depends on the characteristics of the system and the house.
Secondly the offset, currently 34. Altering this is the same as turning a roomstat up or down.
Oh dear, still no joy. There were comments from the residents. The sun went away and storm Jorge arrived so everyone felt cold. I had to intervene at 16:35 to bring it back to life.
Clearly I’m going to need to make it oscillate more aggressively.
I think I’ll have to try some virtual experiments before I do any more practical ones that upset people
It might be a while before I get back to trying that I’m afraid.
Amusingly I did turn it on manually using the vendor application but the accumulator algorithm turned it back off again on the next cycle. It’s a good example of the need to allow multiple agents to control things for comfort.
