Sustainable heating??

In the next couple of years we intend to remodel the back of the house, put in a downstairs shower and toilet, and do various other things.
This will include replacing the current boiler and doing something with the hopeless hot water system - at the moment you have to run the water for a couple of minutes before anything approaching hot water comes through.
Obvious choice is a combi boiler situated close to the kitchen and bathroom to give short pipe runs and on demand hot water.
However this is also an opportunity to 'go green' with for example a heat store, solar water heating on the roof, a wood pellet boiler. This also gives the option of adding other heat sources such as a solid fuel stove with back boiler to heat water in the winter. In this case the pipe runs are likely to be longer but good lagging and a pump may help the 'instant hot water' requirement.
Is this a feasible option? It looks expensive compared to a combi boiler - at least three major components at least compared with one - and the financial (as opposed to moral) payback may be unrealisitically long.
Has anyone gone down this route?
Is anyone contemplating it?
For us it will be a 'now or never' thing as once the house is done we have no intention of mucking about with it for some considerable time.
Cheers
Dave R
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

We have solar heating (for hot water) and it's wonderful. We haven't had the hot water heater on since about May. Our last four or five gas bills have been refunds (compared to our neighbours, who are paying upwards of £1000 pa.)
We have friends who installed a ground source heat pump and they report very good results, but you need a big garden.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've just done the solar panel thing (Navitron evacuated tubes) - still need to burn gas as the weather recently hasn't been that good, but only for 10 minutes each morning now rather than the hour or so before.
Biggest difference is probably the triple insulated tank - it's directly heated from a conventional boiler (standard Y-Plan - not had a chance to change that yet), and additionally heated by a back-boiler in the cooker (Stanley range cooker - bit like a Rayburn), as well as indirectly heated via a coil from the solar panel (which is the only pressurised bit in the system) Internal coil/heat exchanger in the store to provide hot water via a mixing valve to keep the exit temp to 50C
The cooker runs most of the winter, but only weekends in the summer, (it's the only source of heat for that part of the house in winter) so the store ought to be much more efficient at keeping the hot water the cooker generates in a more usable state.
A future plan is to replace the conventional boiler with a log-burner, but the issue then is how to heat the house when we're out for a day in the winter ... I have half-baked plans to dump the store into the radiators, but who knows yet.

If you've got a south facing roof, then go for it. Cost of all the bits for me was just under £2K. (Panel/tubes, tank, pressure vessel, valves and lots of copper pipe & fittings) I only wish now I'd gotten a larger panel and tank!
Gordon
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hard experience is always interesting. I assume this is your £2k total self-installed system?

Can you give any more information on your store (as it's easy to spend £2k on one of those alone!) What is it? Did it have internal coils already, did you add them yourself and were they designed specifically for solar use? Are you monitoring tank temps in this system? Do you see good stratification of hot & cold water, did you attempt to encourage this, and do you think it's important in an efficient system?
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes.
I got the kit from Navitron and they made (or arranged to be made) the tank for me. I had an idea what I wanted, and arranged the details on the phone with them.
I started with this kit:
http://www.navitron.org.uk/product_detail.php?proID@&catID †
and made adjustments on the phone.
The tank is essentially one of these:
http://www.navitron.org.uk/product_detail.php?proID …&catID
It has 2 internal coils - one for the solar loop to dump heat into the tank, and one for the hot water extraction - this is a coil that enters at the bottom, spirals up the full height of the tank and exits at the top. I wish I'd taken some photos through the hole for the immersion heater now (which I fitted with a blanking plug - might put in an electrical immersion heater in the future)
It has 2 other pairs of connectors for direct heating - 22mm and 28mm for the conventional boiler and cooker boiler respectively. These are approx. 1/3 down for the entry and 2/3 down for the exit, just above the inlet for the solar coil.
And finally, it's got a cold feed and expansion bottom and top, respectively which is connected to a small conventional F&E tank in the loft.
So it's a thermal store as opposed to a heat bank. There is no external heat exchanger and associated pump - it's all done via the internal coil which is finned for maximum heat transfer. We live in a soft water area, so I'm not concerned about anything scaling up. (8 years and the kettle is still clean)
The cost from Navitron for the kit just was just over £1,700 - tank, panel/tubes, pump, controller, expansion vessel and some pipe insulation In addition, I bought 15mm and 22mm copper pipes, a few bags of elbows, sleeves, etc. and other misc. items - everything's soldered where possible. I upgraded some existing valves to full-bore levers, changed some leaky pump isolators and so on. (Screwfix to the rescue!) I was able to recycle a lot of old copper tubing from the old setup as I went though.
I have 2 temp sensors in the tank - it came with 10mm tubes fitted to put the sensor into the middle of the tank (they're sealed at the far-end!) The bottom one is in-between the entry & exit of the solar coil, (which in in the bottom quarter of the tank) the top one just under the hot-water exit. There is a 3rd sensor at the solar panel, and that plus the tank bottom sensor is used by the controller to turn the solar loop pump on. (Simple difference which is all programmable in the controler) The 3rd sensor goes into the controller too, but isn't used for anything right now, other than to display it.
I plan to use the top sensor to turn on a heat-dump pump during the summer when the tank temp exceeds 90C to stop it boiling. (The controller can do this)
The tank does seem to naturally stratify and I think this is good. When it's low on heat, reducing the hot water flow makes the most of what's left in it - the cold entering the bottom through the coil does take what little heat is left in the bottom of the tank while leaving the top as hot as possible. I've seen the bottom at 25C and the top at 50C when looking. (I got the cheap controller TDC3, so I can't put it on the house LAN to remotely check it)
Other than convection from the solar coil, water in the tank only gets agitated by the boiler pump - so 10 minutes in the morning, and even then, the bottom of the tank doesn't see much of an increase. (I have the pump set to slowest speed) I've yet to see how the cooker boiler is going to affect it though - I've only done one trial run of it so-far, but we'll be cooking this weekend, so will find out more.
It's still very early days for this yet, so still getting "used" to it and working out how to make maximum savings. E.g. the run to the bathroom takes 20 seconds and it's in 22mm pipe which I can't practically change, so we've decided that we'll wash hands in cold water rather than waste a long 22mm pipe of hot, but we're not afraid to take hot when we need it - the kitchen is much closer and piped in 15mm from the tank, so minimal lag to get hot water.
Not tried filling the bath up yet - I suspect it may require a gas burn if it's not been sunny...
Gordon
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 9 Sep 2009 11:04:40 +0100 someone who may be "David WE

All feasible.
Make sure the thermal store has enough tappings/coils for the sources of heat you might use. Solar needs a coil, assuming you want it to be on a separate circuit filled with antifreeze and pressurised to better resist flashing to steam under stagnation. Other sources of heat and radiators can just be on tappings.
If you are considering underfloor heating this is in many ways best fed by a coil fairly low down the store, to get a better temperature for it, though it is possible to mix down hotter water.
You may want a separate shower coil for mains pressure showers, while having the rest of the hot water system as the better gravity fed system via a separate hot water coil.
If in a hard water area plate heat exchangers are the thing to do for, though they are more expensive.

Is there a problem locating the store near the kitchen and bathroom? The pipes from solar and other heat sources can be well insulated to minimise losses.
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
  Click to see the full signature.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Solar HW usually fails to ever pay its costs off, but its not impossible to make it work financially. Have fun designing a system that will do so. Needles to say professional systems are the least likely to pay their way.
NT
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I agree that if a system is "professionally" installed then the payback time can be very long indeed - mostly due to the so-called professional installers ripping the customers off... (IMO - e.g. a relative paid 4 times what I paid for my system, but she got a 15% grant so that was OK. Err...)
However a DIY install, which is what I've just done ...
The capital outlay for me was just under £2K and it's already saving me money - a mere 10 minutes of gas burn a day rather than the 1-1.5 hours it would normally take to heat the old tank up in the morning. Today the suns been shining all day and the bottom of the tank has gone from 27C to currently 58C and there's another 3-4 hours of usable sunlight to go. At this rate I won't burn any gas tomorow at all.
Now, it can probably be argued that part of my savings has come from having a much more efficient water storage system, but even so - I'm getting free hot water today, and enough for tomorow too!
I have to say, one of the reasons I wanted it wasn't to just save money, but to get-back at the greedy energy company shareholders.. Even so, I appear to be doing both. It will take some time (and a winter) to fully work out the payback time, but I don't care - I can see savings already, so I'm happy.
Gordon (OK, still cavorting about like an evangelical maniac, but I think it's quite exciting!)
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Just out of interest, Gordon - whereabouts are you ? It would be useful to know if it is sunny Spain, not-so sunny Cornwall of definitely un-sunny Scotland.
Rob
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Devon.
Gordon
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

So instead of paying for gas and leccy, you paid other companies for parts that were made using said gas & leccy?
NT
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes.
Gordon
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Boom!.... Boom!
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
We were somewhere around Barstow, on the edge of the desert, when the
something like:

Christ, but that's pathetic. Where's your fire, man? Get in there and promote nukes, or coal-burners or some other manky old technology that will make you money on your shares.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Gordon Henderson

It's no use trying to talk sense to him about diy solar - I would 't be at all suprised if he's in the pay of BNFL to promote nuke power and he certainly has a severe wasp up his arse every time someone mentions solar. Funny, last time I pointed out this was a diy group and I was diy-ing solar, he shut up. Glad to see someone else doing it and putting the nay-sayers' gas at a peep.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Heh... Intersting to read the other comments while shutting up for the past few days... I find it intersting that no-one actually asked me what I think about it all, nor why I was doing it, but rather assumed I'd been conned by the greenies, or hype surrounding it all. Ah well.
All I'll say is that I'm a Geek, Engineer and Scientist in that order, and leave it at that.
Now, anyone replaced central heating system with a home-made controller based round e.g. Arduino? I've only recently realised how crude central heating systems really are regarding their controllers and choices made in them. Must have been a genious of a madman that invented the 3-port valve! MOMO valves would appear to be the way forward, but I guess 30 years ago were quite expensive...
And now to have a free hot bath, heated by the sun and by-product of the cooker. Spent the day with the chainsaw filling the wood store (we have 2 wood stoves, thinking of a 3rd)
Gordon
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gordon Henderson wrote:

Someone asked on Any Questions 'what are you doing about climate change, personally'?
For anyones information, THIS is what I am doing about climate change, personally, telling the facts.
If solar hot water made the slightest sense economically in this country, or saved any significant fraction of CO2 emissions, I'd be for it, even if it was not completely and utterly misleadingly missold.
I am PISSED as hell because some smart talking salesman sold my father in law 2 grands worth of kit, on the promise it would save 'up to half his heating costs' (which run about £2500 a year) when the brochure itself and the figures it quoted showed it would save at most £150 a year, and moreiussu overhauling either.
I am PISSED as hell because it does NOT have an energy meter on it. Just a temperature gauge. He still thinks that because he is 'getting 70C' on the roof, it actually means something. It is a carefully crafted CON trick and he has been ripped off of savings that he really cannot afford to lose.
So yes I DO have a wasp up my ass.
Ad far as nuclear power goes, I am for it because my training as an engineer, my ability to actually do sums and also my time managing financial affairs for businesses show that it is actually the ONLY power generation technology of sufficiently low carbon cost, low actual cost, scalability and energy density to actually SOLVE the problem of the countries energsy needs without wrecking the planet completely.
All other technologies, apart from heat pumps, are simply incapable of supplyinmg more than a very small fraction, and in most cases, at vastly higher costs, and in the case of the so called renewables, at such low energy density that literally MILLIONS of square miles of the country would be needed to be completely covered with them in order to get anywhere near the output thats few nuclear sets could give.
I didn't write it, but I was instrumental in getting it published, because it is the first book that actuality tells the facts:-
www.withouthotair.com
Do yourself a favour, in your smug self righteous selfishness, that you have stuck two radiators on your roof and saved yourself £50 a year, and actually start taking an interest in the real issue: whether or not you or your descendants will be alive in 50 years time.
The FACTS say that without massive nuclear power, you or they will *not* be.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 13 Sep 2009 22:56:44 +0100, The Natural Philosopher wrote:

And I see the author is just about to take up a government post as an advisor in the Department of Energy. I just hope he has the guts and strength of will to kick the politicians into actually doing something that will produce real results instead of just pandering to the media and lining their own nests.
And I suspect Miliband may well regret making this statement "There's no danger of power cuts in the next decade."
http://news.bbc.co.uk/1/hi/uk_politics/8253078.stm
--
Cheers
Dave.




Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 13 Sep 2009 18:56:30 +0000 (UTC) someone who may be Gordon

It is the nay-sayers' loss, you have the hot water no matter how loudly they shout. The sad thing is that the nay-sayers might influence some people.
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
  Click to see the full signature.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David Hansen wrote:

well if you hadn't spent the money on it, you would still have the money, no matter what the greenycons shout.

The dangerous thing is that the greenycons DO influence a LOT of people.
It wouldn't be so bad if
(a) the world could afford it (b) it actually solved the CO2 problem
Not only does it do neither, it also prevents attention being directed at real solutions.
Greenpeace are, by and large, traitors to the human race.

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.