There was such a hard frost last night that the frost-stat on the ch boiler came on for a short time. There was thick ice on all the open water in the garden and all roofs were white.
But it's been sunny today (although cold) and I did three machine loads of washing and we still have a cylinder full of water at just short of 60C.
Scoffers can scoff away but we're very happy -it's just a foretaste of what's to come :-)
Mary
What sort of panels? I'm contemplating doing something with the old radiators, bus windows, and polystyrene sheet that I've got lying around. Currently I'm wondering how hot you could get with silly (say 5 panes) amounts of glazing, with a system to suck air through the panes. So that light absorbed in the panes is not lost.
Also wondering what the possible ratio of a fan assisted panels radiator/panel size is.
A commercial product but self-installed.
Mary
elaborate :-)
Hmm sounds overkill to me. A one metre square panel that I made myself works well enough to give 200 litres plus of water at >80C from around five hours in the sun. Traditional construction of a single panel steel radiator with an aluminium frame, polyurethane insulation, single glazed in 4mm glass.
Did anyone see the Dick Strawbridge thing? His solar panel design was utter pants, a double panel radiator using corrugated PVC glazing.
On Mon, 10 Apr 2006 17:50:54 +0100 someone who may be "Mary Fisher" wrote this:-
Excellent. Now the days are longer you should get a fair amount of hot water.
Perhaps you should sell hot water to the neighbours in the summer:-)
More than we use, I suspect.
They can jolly well get their own systems!!
Mary
That does seem rather unlikely, unless you're starting from something quite warm.
5 hours * 1.3Kw/m^2 (sunlight falling on top of atmosphere) = 23.4MJ 200l of water has 4400J/K/Kg * 200Kg = 880KJ/K. 23.4/0.88 = 26.6K temperature rise.I'd be astonished if you got a real 20C rise out of it.
Your numbers do however work out perfectly for a panel of reasonable construction on mercury :)
"Mary Fisher" wrote
More info please. We are having a new boiler system put in and though we can't afford a whole solar system, can't quite stretch to Jupiter ;-) this year we are specifying a solar compatible dual coil tank with a view to self installing the rest next year.
So as we are trying to find out about other peoples experiences a few questions please.
What brand/type/supplier/cost please? Did you buy a complete kit or did you self source mix and match? And did you find it easy to fit?
TIA
Jake
That's what we did when we moved here 5 years ago.
My local installer sold me a complete kit (less the copper pipe !) - which came with a pretty comprehensive diagram, and the offer of 'hand-holding' if necessary.
It consists of an array of Thermomax evacuated collectors and their header assembly (got the installer to fit that lot on the roof for me and provide pipe stubs through into the loft space). He also supplied the controller and all the necessary brasswork, pump etc.
After I'd done the necessary plumbing and wiring for the controller - he came back and commissioned the system for me - took about an hour. Been running fine ever since - with the occasional slight topping-up of the circulating water.
Don't really know how much money I saved by doing the plumbing myself
- but ISTR that the total kit cost just over £2k. Plumbing wasn't particularly complicated, and the (3) sensors for the controller fitted into metal sleeves (supplied) and the wiring was pre-terminated with plugs - so that was easy.
In terms of performance, I've never formally recorded it - but I know that from about May to September we're not needing much input from the immersion heater to get the DHW up to temperature. Becomes more complicated to assess in winter because the woodburing stove gives priority to the DHW .....
I'd say go for it ! Have tried a complete 'home-brew' system in the past - old radiators, glazed collector etc - but the Thermomax-type tubes are reckoned to capture more heat for a given illumination....
Hope this helps Adrian Suffolk UK fwiw there's a picture of the collector at
======return email munged================= take out the papers and the trash to reply
On Mon, 10 Apr 2006 22:47:39 +0100 someone who may be "Jake" wrote this:-
Mary used a Solartwin panel, for which you wouldn't need a new cylinder, though the existing one must have proper insulation. For DIY this has the advantage of minimum installation time and effort.
For a more involved DIY project Navitron are one source of useful bits.
that it works was established long ago.
Rads are limited by their high water capacity, making for slow response. So solar pv as a control mechanism is out with these. Concentration improves this a lot, and is easy to do with all metal radiators, eg with greased silvered mylar film. Even ali foil works for a while. Concentration improves heat availability in poor weather, financial efficiency or ROI, and system reliability (less plumbing failure points).
Greeenhouse poly could be used under the glass to provide cheap double glazing. Glass absorbs uv which helps the poly last longer, plus it protects it from mechanical stresses. How long its life would extend like that I dont know, but its easy to replace if your panels are ground or wall mounted rather than roof.
I think you'll find its counterproductive. ISTR double glazing gaving the best temp rise for one scenario I calculated. But the real point is output per pound in, not per square metre, or in your case per material use.
If you have a lot of glass, how about a hot air collector with one sheet of glass and one poly?
I still cant see what you mean there
NT
We're in UK.
It's just for domestic hot water - not house heating.
We bought the kit, including a pv panel which powers the pump and all the silicone piping necessary.
It was easy to fit, I can send pictures. If the company had done it it would have been quicker for a straightforward connection to an existing tank but we didn't have one so it was more complicated. And Spouse hates having anyone doing things in the house :-)
The company was friendly, professional and helpful from start to finish, even when we were just thinking about it for six months. The paperwork they provided was excellent.
It's the way to go, I think the capital costs will reduce too but I wish we'd done it years ago when we'd have had more time to enjoy the benefits.
Mary
it does seem optimistic, I wonder if Steve meant the panel was only
1m^2 but had a large external concentrator of some sort?NT
Gee thanks. I'd suggest that the water in the cylinder is stratified. Your figure of 23.4 MJ on the atmosphere is higher than the actual insolation with is about 24MJ/8H according to the local Uni.
I estimate that we should get about 95 litres of water at 80C from this over the day, as I say in practice after 5h water delivered is at 80C.
I presume it's possible that the cylinder remains hot over night, it's difficult to eyeball a cylinder and know how much heat is in it.
Yeah - I was mainly doing the numbers as they seemed surprisingly good, and diddn't accord with what I remembered.
But, if in practice it gives you enough hot water :)
Control systems aren't a problem.
But of course, concentration works best with direct sun.
Yeah - I'll have to do some sums/testing.
I was actually wondering about a scheme which was an air heater alone, for that one. You have a stack of n (where n is a large number of panes, which absorbs say 80% of incoming light before it hits the bottom. The air is drawn past these from the outside in, in a serpentine fashion, so that the inner panels are hottest, and hopefully essentially all IR radiation is trapped. I wouldn't be surprised if 2-300C was possible. But, it'd use a hell of a lot of glass, and probably take a long time to start up, due to thermal inertia.
Possibly - there is an obvious tradeoff (for non evacuated panels) between power output, and maximum temperature. Obviously, adding another layer of glazing will always increase the maximum steady-state temperature, but due to absorbing some light, will decrease the power output. I suspect a 'low temperature' panel, and a high temperature one may be worthwhile.
2m^2 panel, 1m^2 radiator and a fan. Or 0.5m^2 radiator, ...Helps with the thermal inertia thing as well as to some extent the cost.
"Adrian Brentnall" wrote in message news: snipped-for-privacy@4ax.com...
Thanks for the info, very informative. Nice house by the way, bit out of our price range though. Lovely area down there and somewhere I wouldn't mind living even if such an idea is blasphemy for a Norfolk boy :-)
Jake
Thanks for the info. My parents did a while back briefly consider the Solartwin system but didn't go ahead in the end. Think because they had a combi fitted and this made the system impossible or less practical. It's a good idea but we are going for the indirect style system.
Jake
"Mary Fisher" wrote
Thanks for the info Mary, it's much appreciated.
Regards
Jake
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