[Closed] Wood burning stoves (again) & plumbing into a heat store

No direct experience of a back boiler stove, but was toying with the idea before we went for the dual wood furnace/pellet boiler box and a standalone stove instead.

The two things I recall of note were

1) careful planning of pipe routing meant it would therm-syphon well, Otherwise youd need a pump. Of course you may prefer pumped control though.

and 2)
Its not so much capture of heat that might have been lost but taking heat out of the room heating function of the stove. So if you want hot water in the thermal store AND heat in the room then you should have a larger stove than for room heating only. Also, the stove should be run hot to prevent tarring and cooling related deposits forming in the flue because of the cooling effect of the back boiler. Apparently.

How much of all that is rubbish I dont know, but it sounded sensible to me.

Cheers Stoner,

We're going from a nominal 8kw room heat only stove to a 12 (boiler) + 8 kw stove, so I'm hoping there'll be enough heat although it would appear that it baffles down once the water is boiling and so you need a rad on the same circuit in the room as well apparently - I guess we'll have to suck it and see.

One of these looks like a good idea too, but I think we'll try it using a regular gravity circuit and see how it works out first.

http://www.stovesonline.co.uk/wood_burning_stoves/Laddomat-21.html

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Following your inspiration, I've gone for a couple of these 15 tube panels from Navitron

http://www.navitron.org.uk/product_detail.php?proID=289&catID=115

They're solar key marked, so we can register for RHI payment and only pay 5% vat on them (once they've been laundered through my installer friend's books).

Exciting stuff!

very handy being able to use a mate's certifacte. Wish I could have.

I have had a quick look at analysing the contribution of my panels since they went in at the beginning of July and theyve been really excellent. Based on this below, the panels have covered for a bout 40kwh per day of energy that would otherwise have come from burning just less than a bag of pellets (about £2.50ish) so extrapolating looks like around £300-350pa hot water contribution, which without RPI works out at 7-5 years payback as planned

[img] [/img]

Legend:
Yellow vertical stripes are "Heating on". Pale yellow block is "Solar on".
Blue line is No. bags of fuel per day (RH scale). Red dots is smoothed.
Green line and vertical bars are mean air temp.

As you can see, from early July, the solar panels have done all the hot water requirement and potentially could have done so back into May as well.

Good oh, Stoner, it all works as planned then. Our solar panel has covered all of our domestic hot water since the end of April except for a week when we had guests. We'll see how far into September we get before needing an electric top up.

Ace 🙂

Can I show you the "when it rains vs £££'s" chart from our hydro scheme on the We(s)t coast? Due for nearly a 6-figure sum this year, payback in 1.8 years 🙂

yep all going fine so far. Just started fiddling with the pump hysteresis on the boiler/thermal store in an effort to maintain as low a temp at the bottom of the thermal store as possible so as to give the solar array a fighting chance of contributing something over autumn...

Just asked my local weather nut if he can send me his cumulative insolation data by day to see what kind of local irradiance I might be collecting...

EDIT: just to add to that graph, the 0 fuel consumption shown during June is when we were on holiday and the boiler was off.

The approx 0.7-0.8 bags per day shown around the end of june early july is what I think is indicative of summer hot water energy consumption without solar. Where the blue line returns to 1 from september is a projection and Im hoping will stay as low as 0.5 for at least a while yet. but wont know till we go past it.