Re: multi-zone central heating

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

Kevin Hawkins wrote:

I think the best way to
do this is with some form of proportional valve or similar - and playing
with the 'feedback' system will be reasonably fun I think.


Based on a very helpful (and informed) offlist reply I am advised that
the feedback process 'time' on such an implementation would be too long
and that no useful gain would be achieved in such a setup.  I know you
can get thermostats that give a proportional signal out too - ie give a
larger adjustment value out the further you are away from setpoint but I
can see the process time will still be long.  Maybe this feedback of
'room temp' to proportional valve is wrong and it would be better to
have a temp sensor actually on the radiator and modulate my valve based
on that - ie effectively be able to set a radiator temperature. I am
guessing this feedback process could be much tighter (quicker) and more
likely to be stable. Then I could have 'smarts'  that allowed me to
select a radiator temp that maintained the room temp based on my
modelling of the room tehrmodynamics and say the outside temp.   Where
I'm trying to get to is a balanced system where the heat into the
radiator from the boiler exactly balances the radiation and maintains my
set point.

K