which hot water tank

[Annpan]

On our long and winding road to make our home close to habitable 'hot water' has sneaked near the top of our list....

I used to be able to figure this stuff out myself but my brain may actually explode if I try to put anything else in it... so I would really like your help please.

What we have is a single 12 KW woodburner which can be retro fitted with a back boiler - it is one of these http://www.clearviewstoves.com/clearview650.htm

We have no other heat sources in the house at the moment, but a woodburning cooker of some kind is on the wish list, as is solar hotwater (we're not holding our breath for either of these though) we are assuming we'll get a tank with an immerser on it.

The house is very open plan and super insulated. Ideally the house will be heated entirely by this one woodburner and tank, we may want to put radiators in upstairs to spread the heat, but we don't know yet.

We would rather not rely on pumps of any kind as we get frequent power cuts.

We don't know what size we need or what type of tank...
We had thought we were wanting a thermal store/ accumulator tank.... but none of the plumbers we have spoken seem to have any knowledge of what we are talking about.


Any thoughts?

[Big Al]

my perfect set up would be a stove like yours with rads and a tank in the loft. The tank would have preferably 2 coils inside, the first would be fitted to the cold water mains supply so we would have piping hot water at mains pressure. The second coil would be for the solar panels that will go on the roof. The main water held in the tank is heated by the wood burner and this is pumped through the rads etc. I would NOT have an imersion coil in the tank even as an emergency back up purely for the cost of running them. I would soon as prefer to put the wood stover on and boil it''s arse out for 20 minutes in the hieght of summer to get a tank of hot water ( if I didn't have solar on) than use the leccy for heating water. The only downside is that you don't want a pump for power cuts. My suggestion for that problem is to get a battery back up solar power pump for the times you azre without power. I think there is a gravity fed system where cold water sinks and is heated then rises up to the tank but not sure of anything about thast. Thermal store tanks are a posh way of saying a two or three coil tank but if the plumbers don't know about these then how will they plumb them in.
I need to go upstairs to find the name of the tank I want so i'll be back in a bit. You would need an expansion tank for a closed ciecuit system b ecause of the wood stove. (These look like big red balloons)
I believe what I have said is true and safe but I'm sure others will tell me if i'm wrong but pllease check out this for yourself to make sure the system is safe.

http://www.gledhill.net/default.asp
http://www.bhl.co.uk/category/Solar_Com ... _Cylinders

The first link is my favourite tank and I spent a shed load of time researching this topic but the second link is also full of good looking tanks.

HTH

BA


Edited to add links.

[madabouthens]

If you have only radiators upstairs and a hot water tank, the system will work by convection, so no pump needed. Put the tank inline before the radiators. Hope this helps.
Tony

[Annpan]

Thanks :)

We don't have a loft, the tank will have to be on the same level as the radiators.... it is possible we could elevate it by a few feet I guess.

Thanks for the links I'll show them to OH, sounds like you know what you are talking about

[Big Al]

Thanks :)

We don't have a loft, the tank will have to be on the same level as the radiators.... it is possible we could elevate it by a few feet I guess.

Thanks for the links I'll show them to OH, sounds like you know what you are talking about

can I show my son this post please.... he always says I talk a load of sh^&!

[Annpan]

lol

[TheGoodEarth]

Ann - try posting your question here.
http://www.greenbuildingforum.co.uk/newforum/

It's full of experts on exactly this type of stuff done in the greenest possible way.

[kit-e-kate]

Hi, we've got a gledhill tank. Its a Stainless Lite direct type, and its brilliant. Ours is 210 litres and we heat it for about 2 hours off peak, and have tons of piping hot water (at mains pressure) all day. If you were going to run radiators off it, you'd want an indirect one, i think. Gledhill were terrific to deal with and they have a depot in Inverkeithing or somewhere, so delivery was really fast (and maybe free too, i can't remember). I'd highly recommend them.
HTH
Kate
: )

[snapdragon]

Looks like you have the answers - which is good as I can't remember the name of the tank/cylinder we had fitted last year, it's twin coil unvented (one awaiting a solar panel) with an immersion element for 'justincase' and works direct via the mains with no open tanks or header tank for the heating system.

[frozenthunderbolt]

General wisdom is if you are planning to get a solar accumulator - get the largest and most ridiculously insulated tank you can afford to maximise your solar gain - amelortated over cold/dull days. It will then also act as a heat sink/store to help thermo-regulate your home.

[Annpan]

The only problem with thermo-regulating theory is....our house is short on space... well not 'short' really but we are trying to fit a spacious 3 bedroom into a space that can really only accommodate a compact 3 bed.

We have drawn out plan after plan and the only place that a hot water tank can really go is in a storage 'loft' space, which is on the same level as the upper bedrooms but separated from them by a brick wall and only accessible via a loft hatch.

IF I can work out how it can fit into the main body of the house I would much rather do that... but I just can't make it work...

It will of course be SUPER insulated.


... we have had another thought....
we might just get a hot water tank and no radiators running from it.... Our house is pretty much open-plan, with the bedrooms all off of a small landing up an open staircase from the livingroom/kitchen area

Does anyone have any experience with trying to heat a house with just rising/circulating heat just from a woodburner (we are in one of the coldest regions of Scotland, but will have double building regs insulation)

Having looked into it a wee bit, a larger/specialised tank, radiators and a pump would cost in excess of £1000 more to install and
On the coldest days of the year (we're talking -10 to -20ºC for a week or 2 usually) we can bring out some plug in electric heaters for the bedrooms.

Obviously I don't want a cost saving idea to backfire and cost us more in the long term, likewise, I don't want to install a heating system that (and it is entirely possible) is only used for a month a year. I also don't want to make our house difficult to sell in the future (a heating system that has electric backup might just push the right buttons)

any thoughts??

[Big Al]

Initial thoughts before I go shopping is that it might be MORE difficult to sell an electric home in the future if we are to belive the theory that electric prices are set to rise significantly and also the potential breakdown of the grid system thus making electric delivery patchy.

Personally, if all things were equal except for heating in two houses for sale I'd be more inclined to buy a house, even at a premium if it had a mixed heating system or at the very least a potential of a mixed heating system.

For example if one house had a gledhill type tank with a solar coil inside [even if there was no solar panel on the roof], radiators and a wood burner system designed to usea [ proven] thermal rise and fall and a second house with a wood burner and electric back up then I'd go for the first as I would expect ot see rads in a house if it is situated in a cold part of the country.

From how you describe your house it seems as if thermal rise and fall is possible but as for using it in practice I'm not totally oh faye with the principle ecxcept by the idea of heat rising.

Hopefully that will help for now.

[fruitcake]

our house is the opposite way round to you - we've got bedrooms downstairs off a v large hallway, upstairs is totally openplan and unheated - downstairs is underfloor (oil, yeuch). we have a fairly large open spiral staircase and thought the heat would rise - it doesn't, the cold air from upstairs is denser in the winter and 'pours' down the stairs. We've put a woodburner in upstairs now which is v toasty and wonderful. The other thing too is we don't nec overheat downstairs cos it's bedrooms so only heat them to max 15 deg (10 deg or less in the spare).
With your house being superinsulated you might be fine - I heard Gokay Devici (architect) say in a presentation that if you have 1 foot of insulation you dont need to put the heating on unitl it is -1 outside
I agree with the comments re multi power supplies but a lot of folk are now choosing leccy over other supplies as here in scotland it could be mostly renewables - hydro and wind etc. We're looking at switching over from oil to leccy for the summer to heat the water (we dont have the underfloor heating on in the summer) - our tank will do both (i've yet to investigate how many coils it has to see if we could retro fit solar) - its a santon premier plus unvented

[Annpan]

Well.... we EVENTUALLY got to meet with the plumber who had been recommended as he fits a lot of wood-burners to hot water tanks.

It took him 4 weeks to actually show up at the house when he told us he was going to be there.... a bit of a nightmare when we are not living there so have had to make special trips for him not to show up.

so.... because our water tank will have to be sighted on the same floor as the bathroom and en-suite we [according to him] will need a PRESSURISED tank, we had heard that pressurised could be dangerous and had annual maintenance costs too.... and that we have been looking at THERMAL STORES.... his face was blank.... "they feed your hot water taps at mains pressure, because they take it straight off of the mains through a heat-exchanger coil"

"No such thing" says he.... "it couldn't work".... "there is no way".... then he starts with a "what do you do for a living?" "I don't tell you how to run computers do I"

I had to quickly change the subject and laugh off a "you can't believe what you see on the internet"

so our ONLY OPTION [according to him] is a pressurised cylinder... he told us we need a 210l capacity... brilliant! an answer.....

the next day (3 hours later than expected) he came round to "give us prices"

what he actually did was hand us a pricelist from the plumbers merchants.... about 100 tanks of various sizes, vented/unvented/direct/indirect .... not one of the tanks said 210l PRESSURISED so we logged into the good old internet to do the research....


It turns out (and this is after a few hours of searching) that for a wood-burner you need a VENTED cylinder and you cannot have a PRESSURIED VENTED cylinder.... (oxymoron I guess)

So we searched for a "mains pressure hot water vented" and we found this http://www.gledhill.net/page/125/Torren ... ore-OV.htm
which is a THERMAL STORE which feed your hot water taps at mains pressure, because they take it straight off of the mains through a heat-exchanger coil.

These are the things that don't exist, clearly.... the only thing that does exist is an inherently dangerous mix of pressurised hot water cylinder and unstable boiler (which, due to it's fluctuations in temperature, is what a back boiler is)


HONEST TO GOD!!!!!!
WHY IS THE WORLD FULL OF SUCH COMPLETE DICKHEADS!!!!


I'm going to give Gledhill a phone today I'm hoping they can help...... but if I can't find a plumber that can fit the bloody thing it isn't much use is it??

We are seriously considering buying it and doing the whole damned thing ourselves.

OH reckons, once this is all over, we should start a building firm called "We're Not Kunts"

[Thurston Garden]

Ann how are you getting on with this? I had a similar dilemma in my new house. The chat I have been given is that the stove/tank combo must only work on a gravity system. If you relied on a pump, then if the power went down or the pump failed you may boil the system or burn the back out of the boiler.

My set up does not sound much different to yours - super insulated open plan living on gf (my bedrooms are on gf, but at the back of the house) - tank in loft space (your 1f). The maximum pipe run from the stove to the tank is 5m on 28mm piping. Anything longer and the convection flow of hot water won't work.

I am opting for the heat store (despite it apparently not being possible!). MacDonald Tanks in Glenrothes are very helpful. They will be making my tank. I think a thermal store is the only option for me (and maybe you) to get mains pressure hot due to the lack of height on the hot tank which would give low pressure gravity flow.

I really wanted a Clearview Pioneer, but had to settle on a Morso Squirrel which is much cheaper. The stove is the only form of heating in the house. I am hoping not to need to use it very much either. Water from solar thermal will be backed up by the stove which is the principal reason for having it.

TG