Stove Boiler outputs and Chimney Design

[SimonM]

Hi all I posted on this forum in July and was very grateful for the responses I had. Self Build is going slowly but, the first fix has gone very well and concrete guys were a great help.  I am trying to sort out chimney design for a stove with a wrap around boiler. Stove has 4 connections at back A - B at top and C - D at base left to right. Do I need to leave space to side of chimney for two 28mm pipes that will run from point B and T off approx 1m away up 28mm to cylinder and down 22mm to pump for rads (hot) and the same for point D approx 1m away T off 28mm up to expansion cistern and 22mm down linking return (cold) off rads - therefore blanking off A and C

Or would all four A B C & D be used 2 for 28mm pipes for gravity  and 2 connections for central heating therefore requiring spaces on left and right of chimney

And finally is a high and low pipe stat recommended a bloke over a pint mentioned should be thinking of a motorised valve.

Thanks in advance for any advice given - Simon

[sleepybubble]

what you propose seems fine.... with all the usual gubbins about route to vent and heat leak rad etc.....

[Brandon]

I tend to favour the 3 tapping approach, leave one for drain too...

[lightfoot]

Hi Simon,

If you are connecting to just two or all four tappings, then it's a good idea to connect the circuits diagonally, ie connect the 28mm gravity circuit to A-D and/or the CH circuit to B-C etc - this helps to prevent hot spots in the boiler.  Or as Brandon has mentioned - you could use 3 tappings, by combining the returns and utilise a injector tee etc.  I dare say all this will be in your WBS instructions, but here's a example... http://www.charnwood.com/pdfs/Instructions/Co16BWB.pdf

Another option, which is often my preferred method, would be to supply the CH and DHW via a appropriately sized, directly connected (no boiler coils) thermal store - which can be especially useful if you wish to interconnect various heat sources and/or require mains pressure DHW etc - but that's another story and something you may of already considered.


Good luck,

Lightfoot.

[SimonM]

Thanks all its great to get the right answers - Cheers Simon

[SimonM]

Hi I have spent a good part of the day reading threads about Load  valves and load  Units - In your opinion would a load unit be a  good investment for my setup as described / tweaked above and flue stats or pipe stats ??

[Brandon]

Yes if you are going in directly  to a store (as you ought with a new install )

What size stove? (as in output to water in kWh?)

What size store (litres)

EDIT: oh and flue stats in preference

[SteveH]

EDIT: oh and flue stats in preference

 More info please Brandon (Prity please, really )

 I now have my Scanline 580 Aqua (Lovely bit of kit, multitube boiler) & need to make a sensible connection to the Akvantti 1400EK ( Indirect UFH output).

  Already have the boiler thermostat sorted but would like to "series" it with a flue temp stat to save turning the stove into an inefficient Rad as the fire dies...

[SimonM]

Hi, Stove output to water is 13 kwh max aiming to to connect to an approx 300 litre solar cylinder or twin coil indirect cylinder with the addition of 60 tubes but thats a thread for a latter date -  cheers for pointing to flue stats I shall look these up  and from the new post multi tube boilers ££?? Thanks Simon

[lightfoot]

For a bit more info on flue stats, see this thread.... http://www.navitron.org.uk/forum/index.php/topic,8691.0.html


PS, Hi SteveH - out of interest, why are you connecting the UFH indirectly to the thermal store and/or was you planning to connect the WBS indirectly?

[SteveH]

For a bit more info on flue stats, see this thread.... http://www.navitron.org.uk/forum/index.php/topic,8691.0.html

  Hi LF,

  Spec for our Crete heating changed a little... Total lack of competence out here... As my local plumber said "Come winter everybody heats the village & not their home"... at least I have one person that understands.

 Now we are using an Aventii 1500 litere accumulator running up to +80°C with thermal mixing valve, instead of a home-brew 3,000l plastic barrel store running to 50°C max & I was uncertain about keeping within the Akvaterm 1.5 Bar limit. Decided that it was better to hedge my betts & go indirect on the UFH circuit, as if I failed to get it correct with the solar input I can direct couple to a heating system on this circuit. I have also arranged to have the same option on the DHW Cylinder system too.

 If this personal foray into the unknown all goes wrong, I want to sell quick, & if the system has room to revert to something simple & locally understood, & has the selling point of being energy efficient (exterior insulation) then it is easier to sell.

 I am Eco but I need to cover my arse....

 Just noticed I didn't answer the part about the WBS... this is indirect through the DHW TS & Direct to the Accumulator. That keeps all the steel components on one curcit & separate from the UFH & DHW TS (Copper & Pex). I have the accumulator open vented in the current design, but need to change this when I source a 150 litere expansion vessel.

[SimonM]

Hi before call it night nagging question - I do not know yet what my well pressure / extraction rate will be and so have assumed indirect cyclinder with large coffin tank would be better than a thermal store ? Would it actually make any difference 3 showers and two baths and 3 toilets in build probably being too traditional ? Cheers and SteveH goodluck with Crete if things have not gone wrong yet you must be one of the lucky ones.

[Brandon]

a 1000l store tank that feeds a pressure pump, vessel etc, and thence to a thermal store (just finishing one like that now...)

[SteveH]

For a bit more info on flue stats, see this thread.... http://www.navitron.org.uk/forum/index.php/topic,8691.0.html

 Just posted the flue stat spec on the above linked thread... Thanks for pointing me to it...

...SteveH goodluck with Crete if things have not gone wrong yet you must be one of the lucky ones.

 Thanks Simon... it seems to be an "Attitude of mind" thing in Greece... you have to look at things from the "Didn't go completely right" angle. A friend Alan, who has been living on Crete for many years, gave me some good advice, "When you see somebody doing somthing "Barking mad" here, don't ask yourself "Why" ask "Why not"

 Have a fun Stove install....Yamas!

[SimonM]

Hi all after many hours of reading through posts on the Navitron forum I have come to realise that a thermal store would be a much better approach than sticking with the traditional indirect cylinder. I can see the logic of having a 1000l store outside and a single pump providing mains pressure - plumbing certainly sounds less complicated. I shall have to return to the drawing board