Heating controls for multiple heating sources

[Onetap]

Their latest header has a twin helical spiral inside to direct water flow which they hold a patent for.

http://www.systemlink.ie/products-59/spirozone.html

Looks like another good invention and innovative product from the Irish.

I'm sure there is some logic behind the design of that device but I cannot see it.

 

[Norcon]

internal pressure activated valves

It seems they have fitted a by pass valve inside the manifold.
Probably accessible from one end.
But how it would be adjusted seems a mystery.

I think compactness may be its selling point.

They fit internal baffles inside their normal connection headers.

http://www.systemlink.ie/images/sto...s/SystemZone_Manifold-General_Information.pdf

No NRV's needed for this one but they recommend them for the spiral manifold.

 

[nads1978]

This fandangled spiral-ma-job, do the fluids from each system mix? I guess they must. I think that all heat sources supply the spiral-ma-bob (& mix) and then each system that requires heat just draws with its own pump.
Am I right?

 

[Norcon]

The spiro zone is a pipe inside a pipe. The inner pipe has a slot which is cut on the flow side from the boiler so that flows to the outer chamber around the spirals past the other flow ports.
And a slot in the other end which returns from the return spiral past the return ports.

So it seems to be acting as a split flow and return common header inside a compact unit.

And I would say mixing is minimal.

The inner by pass need only have enough differential pressure to overcome the resistance of the flow spiral.

Figure 2 in the following link shows the oil/gas boiler connected to the outer chamber which will house the flow directing spiral.
But where exactly is the by-pass in this case?
http://www.systemlink.ie/images/sto... Installation Instructions - Rev3 - Aug12.pdf

Figure 3 shows the oil/gas boiler connected to the end of the manifold which would suggest the inner pipe.

It may be nothing more than an NRV with a known pressure drop they have used for the by pass. Though I could be wrong.

Crazy money for this device.....
http://www.stovesonline.co.uk/wood_burning_stoves/SpiroZone.html

 

[nads1978]

Whilst I like the idea of the thermal store, I feel it will probably cost too much, as well as all the configuration that is required.

Using the SpiroZone, would the following diagram be roughly right? As a concept. Not too worried about the finer details or controls yet, just main principles. The Hot water I am happy to come from oil boiler only, as I also have the immersion.

1) Will the one connection to header tank be okay, will the SpiroZone allow for the filling of the other circuits as drawn?

2) How I have connected the air separators, on a common riser, is this acceptable practice? (Do I need the NRVs?)

3) Do I need a 'heat dump' radiator in any circuit? (what function do they serve, is it protection from over heating the boiler by means of a motorised valve?)

Thanks.

 

[SimonH2]

There are so many things wrong with that.
Your UFH needs to be on it's own circuit as it has different timing and temperature requirements to the rads.

But the real biggie is that, while I'm no expert, I'm pretty sure that arrangement is not allowed for the wood burner - pump goes off (turned off, failed, power cut, whatever) and you have no flow and no heat load.

Seriously, make yourself a neutral buffer - just needs a domestic HW cylinder and add some extra tappings if you are on a tight budget. Then the wood burner can be a gravity loop, as can a heat dump of some sort.
Plus, it will make everything else just so simple you'll wonder why it's not standard practice.

 

[Norcon]

Quite a lot wrong with the first drawing also and not the first time on this forum schematics were not representative of the actual system.

 

[nads1978]

not the first time on this forum schematics were not representative of the actual system.

The schematic is accurate, the plumbing is a mess.

 

[Norcon]

Rip it out and start again then.

I'm plumbing my own in shortly which will not be linked to the existing system but will heat three high output column radiators and eventually the cylinder.

The only controls I'll need are a set of hi-lo stats.

 

[SimonH2]

Here's a suggestion of what I believe you should aim for.

Untitled

• SimonH2
• 2 Oct 2013
• 1

Note that the wood burner has a simple convection circuit to the buffer - no valves, no pumps, just natural convection. There may be a requirement for some valves (thermostatic vale on the hot flow ?) to avoid the WBS running too cold - I'll leave the experts to debate that one. Also not shown is any form of heat dump, which could just be a thermostatic valve and a radiator on a convection circuit - again the experts can advise on that.

Note the TMV on the UFH - without it you'll overheat the system.

The rads can be all TRV if you fit a modulating pump. This works very nicely and will give you a quiet system. EDIT: No need for a bypass at all - just let the modulating pump back off as the TRVs close.

For DHW you have a number of options as shown at the bottom of the drawing.

On some of the circuits, there may be a need for a check valve. Not so much to stop reverse flows, but just to avoid convection circulation when you don't want it. That will depend heavily on the layout - eg if the buffer tank is low down (like the thermal store in the garage underneath my flat) then the rad circuit will readily thermosyphon.

The position of the tappings is roughly as I'd probably do them - although I should have drawn the CH takeoff below the level of the heat imputs (ie the boiler and WBS should go in higher up). The heat sources go in part way from the top so that if they are supplying water at lower than the buffer temperature (as the boiler in particular may do when starting up) it will leave some hot in the top for the benefit of the DHW - particularly important with a heat bank or thermal store.
The rads come off highest up as they want the warmest water, then the UFH. The UFH return will generally be warmer than that from the rads - hence the rads returning to the bottom of the buffer and the UFH a bit higher up.
So the heat sources supply hot water, then the various loads take a bite before it's eventually drawn out cool from the bottom to be reheated - if set up right it will certainly help in keeping the boiler in condensing mode.

 

[nads1978]

Rip it out and start again then

Looks to be likely!

Here's a suggestion of what I believe you should aim for.

Wow, thanks, some really great information there. Much appreciated.

Just need to decide if my long/high run of 22mm from the Log burner is going to work, I may have to put the/a tank near to the log burner.