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Thankyou everyone for your suggestions. I'm still considering the best solution, and have also been made aware of some soya based paint which although expensive apparently covers amazingly well, so might do the job economically in only one coat.
At least well enough for a plant room…….
Mike.
Yes interesting idea – but I wonder how well it would adhere to polystyrene??
19 August 2010 at 7:57 pm in reply to: Re: Re: Looking for Contractor to quote on £1.5m contract #36855You could do a lot worse than speak to Mike Neate of Eco-DC. He's currently in the final stages of building my ultra low-energy autonomous house in Worcestershire, but he works anywhere in the UK, moving his base as necessary.
Besides having trained as an architect, Mike also has specialist environmental building & project management expertise, and his new business partner Graham King has considerable experience in the mainstream building industry. The two of them are actively seeking to expand their company into larger 'eco' projects of the kind you've described.
You can contact Mike on 07872 527 539.
No — I'm hoping to, but am finding it difficult to locate anything suitable. I started a thread on this very topic a while ago:
https://aecb.net/forum/index.php?topic=1735.0Another flurry of research recently has unfortunately failed to locate a suitable product, at least in the UK.
There are one or two still under development, but nothing actually available, as far as I can tell.
Actually there is the GFX heat exchanger, but that requires a vertical drop which I don't have.
I must re-visit some of the replies in the previous thread, and see if there are any developments.Mike.
Yes very interesting Barry, thankyou. Unfortunately I fear we're too far down the design/planning road to make such fundamental changes at this stage, even though I can see the potential benefits. Also our south elevation is already pretty well full of glazing to maximise passive solar heat gain, so there wouldn't be much room left for a large solar array.
I'm trying to make best possible use of the solar water panels we will have by using a very large tank (500L or more) and surrounding it with lots of insulation. I must confess that although I have at least some idea of how most of the systems in the house are to be implemented, I'm still floundering somewhat with the water heating system, despite several helpful suggestions.
We're hoping to start construction very soon, so decisions will have to be made….
Even though it was co-developed with Mira who sell mainly (only??) electric showers, I understand the Warmit device can be used with other systems, e.g combi boiler, DHW cylinder with solar, and so on. In this case the heat exchanger's plumbed into the cold feed to the shower, and the recommendation is to use a thermostatic valve to keep the temperature stable.
Without one, fairly obviously, as the exchanger warms up during the shower the water will progressively get hotter and hotter.
Assuming what I've been told is true, and the device will work in this way, I'm very tempted to try it, as long as it's available by the time I'm installing plumbing.
(We haven't started building yet….)Mike.
Well it seems to get more confusing the further you venture into it.
I'd already found most of the possible systems in Tom's very comprehensive list, several of which are interesting. I also spoke to the company in Hereford mentioned above by Nick. Alastair Green at AKI Plastic Mouldings told me they're hoping to start manufacturing a shower waste heat exchanger developed in collaboration with Mira, at a target price of around £150 to 200. It's about 5cm high and is a moulded plastic device which couples directly to the shower tray outlet, and has a heat exchanger through which you feed the incoming cold water.
http://www.aki.co.uk/page/warmitIf it works (he quoted 40% efficiency) and the price is under £200 it might be worth considering. If not & I'm feeling creative with my blowlamp I might try Peter's concentric copper waste pipe idea although bearing the cost of copper in mind the AKI/Mira unit might not be much dearer(!)
Just a quick p.s. – Alastair at AKI told me they'd also been involved with 'Low Heat' – a system to recover heat from all waste water. That's been shelved for now due to disappointing performance. He also mentioned that they'd been offered an import deal for the GFX device some time ago, but didn't take it up because they tested it & found the performance wanting. I'm not sure I'm supposed to be telling you this.
Andy – Hello – Yes an alcohol stove had been mentioned to me already & sounds like an interesting device. My reservation is that in aiming to service my house from its immediate surroundings I have access to a free supply of local wood, which is likely to be burnt anyway, if not by me. In a modern, efficient wood stove I could burn it clean & hot, and realistically would probably only do so 2 or 3 times a year.
Actually the proposed location for it is in the hall, not the main living area, so a view of the flames isn't a deciding factor. But a small efficient stove with an external air intake – so sealed off from the house – and with a chimney valve to prevent a through-draught when not firing – would, I think, lead to relatively little quiescent heat loss?
I still really can't decide on this to be honest – I've had highly credible advice both for & against. I'm further confounded by a theory espoused by some (James Lovelock in 'Revenge of Gaia' et al) that we *need* particulate emissions to contribute to 'the parasol' – a layer of atmospheric pollution which shields us from the sun, and so partially mitigates the effects of global warming. Notably this 'global dimming' phenomenon was reduced for a few days following the 2001 US terrorist attacks, when widespread grounding of aircraft led to a reduction in particulate pollution & a greater penetration of solar heat energy. As a result, there was a marked increase in temperatures, until the pollution returned to normal levels.
This BBC Horizon programme covered it in some detail:
http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_prog_summary.shtmlSo a good old fashioned filthy wood stove to produce plenty of particulates to help shield us from the worst effects of solar radiation then??
Confused – I've every right to be!!
Thankyou Steve – I've been working on around 2½kW of PV capacity, plus a similar amount of wind power, assuming that we'll be allowed install it. If not then there's room to up the PV capacity, as the array will be mounted on a pergola in the garden, and not on the roof. I'm assuming (although maybe wrongly?) that economies of scale & technological improvements will make PV a little more economical in future than it is now. Of course a combination of wind/PV would give a more balanced overall output.
But as you say:
Keep it simple – you will have enough to worry about when work starts on site without fretting about the heating and DHW system!
Which is what I think I should do for now, as other considerations are beginning to come to the fore, and the house can be pretty well completed before we have to commit totally to one water heating system or another.
Following on from Dave Howarth's comments though, and at the risk of incurring the wrath of David{!}, I think I'm probably sold on some kind of wood burner for emergency space & water backup. This has to be seen in the context of all the other (less efficient) wood burning stoves in just our own village, plus the people in the historic buildings in the conservation area with logs smouldering slowly all winter in their picturesque inglenook fireplaces. A very occasional fast burn of well-seasoned wood in a Lenius (or equivalent) stove will contribute such a tiny amount of pollution I really can't see what harm it can do.
But it's also worth bearing in mind that this is *purely* for emergency freezing-winter-weather backup, so if the zero-heat house works as we're hoping it will, we'll never need to light this burner anyway, so it'll end up as a rather costly ornament.
But I'd rather have an insurance policy.
Mike.
Steve,
This thread has become quite long, but right back at the top you'll see my proposal is exactly as you suggest – the majority of DHW from large roof-mounted solar panels, assisted by a little clean wood burning in the coldest weather. So the immersion heater would only be providing a small %age of topping up, from PV (+ eventually wind?) and offset grid electricity.
Actually if you're going to use a turbine for offset then that *is* a good option in a way if you can use immersion heaters as a dump load in times of very high wind. I'm not sure what you do beyond that once your thermal store is boiling though. 😉
Of course David's a recognised authority in this field & puts forward erudite reasoning as to why I *shouldn't* do it this way. I think when you've tried to strip everything down to a minimum as I'm trying to do for this design an element of personal opinion begins to come into play about where you stop, or what compromises to make in taking efficiency / emission reductions even further.
By contrast if a group of us were to consider how to improve the environmental impact of the Victorian semi-detached house I live in at the moment, a discussion like this would be unnecessary, & I wouldn't have time to post here anyway, as I'd be too busy installing insulation…….
Mike.
Oh just found your blog BTW – very interesting project.
David, thankyou. Actually we're already monitoring Freecycle, although the quantities involved (>10k?) make it a bit of a long shot.
Had just realised (a bit late?!) that most bricks tend to come from cities though, so are planning a lovely day out in Birmingham to see if we can find anything of interest.
Having initially been unsure, I feel on reflection that we ought to try to use reclaimed bricks in a build of this kind if we possibly can.
Mike.
David,
Actually our architect Neill Lewis had already suggested this kind of cargo might be used as ballast, and a man we spoke to at another salvage yard confirmed this is usually the case. If so then I guess it's not so bad (ships would've been carrying ballast anyway), although I note your comments on the unknowns of shipping fuel oil pollution. The flagstones you mention, plus quite a number of other materials are apparently being imported quite extensively from India & Turkey.
It sounds as though we should keep looking for more local reclaimed bricks if possible, but if the Indian ones are the real favourites in the end they'd still be preferable to brand new?
I'd welcome any further thoughts if anyone has them on this.
(Or any bricks…….!!)Mike.
Mark many thanks – plenty to think about there…..
P.S. Have you read the Autonomous House by Robert and Brenda Vale? If not this would be a good port of call for predicting water use and many other aspects of low carbon design.
I can go one better than reading the book – I've been there!!
Gosh Chris lots of questions………but I'll do my best to answer – I realise this is a more complex matter than it at first appears.
My own (reasonably carefully researched) calculations are 45 to 50L total water use per person per day, although I don't know what percentage would be hot water in practice. It's worth mentioning that the nominal design is based occupation by an energy-aware family of four. This is simply because you have to look to the future and assume the house will be around a lot longer than we are, so we're designing for more than the two intended original occupants. Our imaginary family would consume around 1200 to 1300L per week, and our proposed solar installation (3x Velux U12 collectors) takes account of this.
We'll most likely continue to use our A rated washing machine (it's a Miele with many more years left in it & it would be crazy & expensive to scrap it). If we have a dishwasher it'll have to be bought new, so can be highly efficient A++ or whatever.
We have a healthy attitude to washing & hygiene – we attend to both when we need to but are aware of the use of valuable resources so we don't indulge. We're not three-showers-a-day people.
I wouldn't rule out a small wood burner – wood supplies in the village are plentiful and free, and if we had the right appliance we could presumably burn it pretty cleanly. If *we* didn't burn it someone else probably wood, smouldering away atmospherically(!) in their picturesque inglenook fireplace.
More extreme solutions? I'm intrigued — heat pumps don't look very promising for producing the temperatures required for DHW. We have the space – a large cellar for water tanks & composting toilet chamber. Money depends on how much & how worthwhile it would be.
Cooking's still under consideration. I'm planning quite a generous PV installation. Ideally I'd like to be net zero carbon. I'm not going to mention cooking with electricity.
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