Free (almost) solar panels

[Andy Hamilton]

I recently heard of a woman who painted an old radiator black, filled it with anti freeze and water and runs her hot water off it - how cool is that.

How hard is it to do the same do you think? Could I get away with this in a rented house, well I guess the landlord would have to give me permission although there is nothing in the contract about fitting your own heating system.

[chadspad]

Didnt they do something similar in that 'Its not easy being Green' programme for the showers outside to have hot water? Seems like an excellent idea

[Muddypause]

I've thought of doing something similar, ideally mounting the radiator in an insulated frame with a glass front.

I think I would make a sort of temporary thing on a slanting stand on the ground outside the kitchen window, and piped indoors to a heat exchanger (eg, small car radiator) inside a small tank next that would sit next to the sink. Probably need a little pump like a garden fountain to circulate it. In effect it would be a 'pre-heated' water tank, that I could fill the kettle with, or use as cooking water, so it takes less energy to get the water to boiling point.

Doing it this way would mean there is no connection to the existing plumbing, and nothing is a permanent fixture. The only challenge that would need to be made landlord-proof would be the way you get the pipes from outside to inside.

[Martin]

It's a touch more difficult to get right, but you can get them to "do it naturally" without a pump - you need the radiator as low as possible, and the collector tank as high as possible - it should thermosyphon! It may be an idea to work out some form of cut off to prevent it circulating at night - the trouble with all flat plate panels is that they are as good at radiating the heat as they are at taking it in!
I am at the moment awaiting arrival of a patented "heat saver" device to try out - it's essentially a simple heat exchanger, with what's claimed to be a "novel way" of introducing the hot water to the tank! Cheap it isn't (£350), but it may have some advantages - will let you all know when I do!

[Martin]

or howsabout one of these? - £320 plus delivery



An all-in-one solution - made for real "backwoods stuff" - simple tank heated by evacuated tubes - highly efficient - lag that up, all you need is some piping!.........

[Lord Azrael]

That looks interesting, and theoretically a more affordable option depending on what it can heat up. If it could do a bit of hot water for my bath at night and save me using the immersion heater I'd be happy 8)

[Martin]

it comes in various sizes, and numbers of tubes - they're designed to freestand - you just fill the tank, let it heat, and use it! - the 15 tube model is £320, and that is about three quarters of the tubes we'd use on a typical home system, so there is a lot of heating potential - you then choose the tank size according to your needs. 8)

[Martin]

and before someone asks "why vacuum tubes?"
- they are more efficient than flat panels, and "hang on" to more of what they grab (only something like 7% escapes), and work better at the beginning and end of the season than flat plates
Contrary to what a lot of overpriced companies would have you believe, these are a Chinese invention! Under development since the early 80's in a Chinese university, they are now made in their millions in China for the global market - many panels you "think" are German or Swiss come off the same production lines as our openly "chinese" ones! 8)
Many people think the vacuum tubes contain water - they don't! (not in the sense they mean it anyway) - the water just circulates through the "manifold" at the top - the heat is transferred to it by the use of "heat pipes" inside the vacuum Tubes.
If anyone's interested, I was fascinated by the beautiful use of simple physical properties - a really "elegant" way of doing it - the heat pipe is rather like an "upside down thermometer" in copper - inside the tube is a small quantity of what some companies call a "safe, non-toxic heat transfer fluid" - it's water! - the heat from the sun passes through the outer vacuum tubes - (black on the outside, silver on the inside), and heats the copper tube - the tiny amount of water inside the heat pipe then boils, taking the latent heat of vapourisation of water from the sun - it travels up to the "fat thermometer" end of the heat pipe, and the steam condenses at that end - giving up all that lovely "latent heat" - this then transfers into the manifold, which heats the water!


probably clear as mud!

[Andy Hamilton]

hmm £300 quid is really out of my price range £30 is more like it. I like the sound of a free standing one and I have a small window in my kitchen that I could run a pipe into so it would be landlord proof. Only been around once since we moved in October though.

Back to the point, I think you have filled in the gaps there muddy I will start looking in skips for the radiator. - I wonder if I can the other parts from freecycle? Emma would certainly love a contraption that gives her hot water for tea whenever she wants it, I can see our tea bag bill being higher than the money it could save though.

[Martin]

- the radiator, box, glass etc, you should be able to blag - ideally site it right down near the ground, THEN run the pipes (rising and falling) through the window, and have a small tank sitting on top of a cupboard or something - a small header tank can be used - stick it in an insulated box, and away ye go! - just top it up with a hose regularly! If you can, stop it circulating at night!
Martin's "skip special!"

[Andy Hamilton]

I think I will have a go at this as soon as I find a radiator in a skip. - I would ask on freecycle but I don't fancy strapping that to the back of my bike

[Martin]

or for summer use, especially for hot drinks, think solar ovens! - there's several sites out there that have simple plans using cardboard and aluminium foil to make reflectors - you put something like a black painted beer can full of water at the point of focus...........

[Martin]

remember to go for a "single" radiator - often there's two attached back to back

[Andy Hamilton]

or for summer use, especially for hot drinks, think solar ovens! - there's several sites out there that have simple plans using cardboard and aluminium foil to make reflectors - you put something like a black painted beer can full of water at the point of focus...........

Several sites including this one mate http://www.selfsufficientish.com/nevssolaroven.htm by Nev (wombat)

[Wombat]

Hey Martin!

I was reading on another forum that there was a local energy show that included these little beauties (I was looking at replacing my flat plate collector but at $2000+ it gave me pause for thought) The guy said that the stand where they were on, some one nudged a tube and it fell about 6 inches (one end anyway) causing it to implode scaring the hell out of everyone.

Conclusion: They are too fragile to survive a hail storm or bird strike.

your comments?

Nev