scottishjohn

complicated heating source controller

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anybody know a of controller that can work with lots of inputs  to control multiple heat sources .so you can decide at what temp a particular device kicks in  and then at what temp t changes over to  another source .

 

I tried to find one years ago when I had solar and thermal store which was also connected to gas boiler  -problem was  to let solar have 

priority when it could make heat,even small amounts  to get most hours of usage  in a day  and not just have boiler take over as soon as  temp got too low 

would need to be able to work on clock settings as well .

example early morning --you have showers and ufh is on --tank gets partially depleted ,but you know by 8 or 9 am there will be enough solar to fill it up again and gas won,t need to come on at all ,so you only need gas to come on if temp drops below min ufh temp  and once solar is above min that kicks in and turns gas off.

I made a simple analog system with min and max thermostats   but not as good as it could have been with  "what if program "for want of a better word 

It relied basically on the thermal separation in my very tall thermal store which had 3 coils,solar in  and ufh out and dhw out at top  and also a heat input to parent volume if needed for gas intervention 

If such a controller is made then maybe i would have 4th   for ASHP  or gas coil instead of stirring up parent volume .

only thing i could find at the time was very expensive h/vac process  controller for a large building ,which ran off a computer .

or maybe i just have to build and even taller tank to get better separtion  still 

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If it needs to be programmable/customisable/bespoke then perhaps a PLC? Google says there are cheap ones available...

 

https://www.allaboutcircuits.com/news/low-cost-programmable-logic-controllers-for-the-frugal-engineer/

 

https://www.t-uk.co.uk/products/plcs-with-integrated-hmis/micro-plcs/

 

Never used one but thing they use Ladder Logic..

https://www.plcacademy.com/ladder-logic-tutorial/

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3 hours ago, Temp said:

If it needs to be programmable/customisable/bespoke then perhaps a PLC? Google says there are cheap ones available...

 

https://www.allaboutcircuits.com/news/low-cost-programmable-logic-controllers-for-the-frugal-engineer/

 

https://www.t-uk.co.uk/products/plcs-with-integrated-hmis/micro-plcs/

 

Never used one but thing they use Ladder Logic..

https://www.plcacademy.com/ladder-logic-tutorial/

  PLC,

yes that rings a bell now

was hoping for something a bit less pc based --will have a look on the net anyway 

I am a ludite 

and by look of them I would need a  load of relays to actually work things .

I was hoping someone had made a different unit 20 years on from last time i looked at this

I,ll give it some more thought  didn,t really want to have a take programming course  to do this.

my hard drive is already pretty full  and running out of RAM at my age . LOL

maybe cascaded thermal stores and back to analog thermostats  +relays would be simpler for me 

thanks for reply 

Edited by scottishjohn

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I must admit I'm of a similar mind to @scottishjohn and am focussing on a low-tech solution. The TS I'll be using (Harlequin Heatstream) has a C/O stat on each input coil and the coils are zoned within the tank. Between these, the microswitches in the motor valves, a couple of roomstats and (possibly) a cheap PID controller, I reckon there's plenty of options for marshalling energy in and out of the system...

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If you have not got thermal store yet ,then from my experience runningmultiple input +output coils  ,there is no ready made thermal store that is ideal .

reason is simple a tall tank is not easily fitted in most houses as a retro fit  and stratification of heat in tank and  keeping the  internal flow of the tank very low ,just vertical if possible is the key to getting best solution 

the best ready made solution i have seen is the SOLVIS MAX --german -no uk agent 

old video of how it works 

you could change oil or gas input for anything  if you wanted .

my thoughts are to get similar made but taller ,as this unit is only 500litres

 

Edited by scottishjohn

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The usual way to combiner multiple heat sources is with a neutraliser, a friend has 3 heat sources into one tank with such a device and it seems to work okay.

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3 minutes ago, ProDave said:

The usual way to combiner multiple heat sources is with a neutraliser, a friend has 3 heat sources into one tank with such a device and it seems to work okay.

yes but really is an afterthought way of doing it -If you have  nothing to start with then this must be a better way ,and the neutraliser would not address the solar problem .

where the oil burner goes could be solar pv element,if you are that way inclined 

 

 

Edited by scottishjohn

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