emsfactory
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| posted on 7/6/09 at 01:36 PM |
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Made a solar air heater!
Nout to do with cars but thought some of you may be interested, have some opinions on improvements.
I built an air heater from old cans and the air has to travel horizontaly through all the cans. Works now on convection only,
not blown through yet.
Just had it sitting in the porch yesterday and with the sun on it had an 11 degree increase in temp between ambient and exhaust. 11 degree celcius!
Anyone made one?
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emsfactory
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| posted on 7/6/09 at 01:37 PM |
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air heater 1
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[Edited on 7/6/09 by emsfactory]
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WestfieldSEI
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 posted on 7/6/09 at 02:00 PM |
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top idea
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smart51
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| posted on 7/6/09 at 03:22 PM |
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I made a solar water heater. depending on the flow rate, I could get 50° on a reasonably sunny day. I've no idea why the "proper"
ones cost so much.
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nitram38
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| posted on 7/6/09 at 04:21 PM |
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Have I missed something?
On a hot day you want to make something that traps heat?
What will you do with it?
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JoelP
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| posted on 7/6/09 at 04:27 PM |
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i saw a really good product in a camping shop the other week, it was a solar shower bag. Basically a black bag of water that you hang in the sun to
warm up. Eventually its warm enough for a shower and you just open a valve and the water sprinkles out the bottom. This is a brilliant way to save
money in summer as having a shower is one of the most energy demanding things we do at home.
If you could get used to the water being a bit colder, i bet you could use it on sunny winter days too.
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emsfactory
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| posted on 7/6/09 at 04:29 PM |
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its more for the winter. On the very cold days there is usually a lot of sun. I intend on making one to heat the garage up on the very cold days. This
is a prototype.
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MautoK
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| posted on 7/6/09 at 04:35 PM |
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Any teeth left after all that fizzy drink? 
Brilliant idea, though - good job!
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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mistergrumpy
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| posted on 7/6/09 at 04:58 PM |
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I think you should be concerned about his liver. They look bigger than pop cans and more like alcohol cans
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Badger_McLetcher
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| posted on 7/6/09 at 05:01 PM |
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Locost intercooler anyone? lol
If disfunction is a function, then I must be some kind of genius.
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Guinness
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| posted on 7/6/09 at 05:59 PM |
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Interesting.
How did you seal the cans together? Weld or sealant?
Or does the pressure of the end plates hold them together?
Cheers
Mike
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emsfactory
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| posted on 7/6/09 at 06:31 PM |
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Liver is the one to be concerned with.
FYI if you try this yourself wash the cans as you get them. Leaving them in a box in the garage for months generates some funky smells and goo.
The cans are just stuck together with silicone.
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splitrivet
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| posted on 7/6/09 at 07:45 PM |
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Just the thing to warm up the garage on those cold winter nights, or am I missing something.
Cheers,
Bob
I used to be a Werewolf but I'm alright nowwoooooooooooooo
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MikeRJ
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| posted on 7/6/09 at 10:24 PM |
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If you using convection, shouldn't it be stood up on it's end?
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emsfactory
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| posted on 8/6/09 at 12:49 AM |
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No.
It is baffled so it has to go through allthe pipes. Intake is at the bottom and the output is at the top so it is forced to convect.
This evening in low sun, no clouds, ambient 24 exhaust 40. Highest so far.
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MikeRJ
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| posted on 8/6/09 at 08:08 AM |
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quote:
Originally posted by emsfactory
No.
It is baffled so it has to go through allthe pipes. Intake is at the bottom and the output is at the top so it is forced to convect.
Still not convinced that convection will be very efficient with horizontal tubes, since convection naturaly occurs in a vertical direction.
Within each tube the warm air will rise to the top half of the tubes, but convenction won't force the air to exit out of one particular end of
the tubes?
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emsfactory
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| posted on 8/6/09 at 09:45 AM |
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It wouldn't your right but the tubes are all joined together in a big snake through the headers. Even just the air rising in the headers will
push the air through in the required direction.
I wasn't sure myself if it would work or not but the top hole gets a lot hotter than the bottom one does.
I am still just playing really. I figured that if the air had to travel through all the pipes then the air would collect more heat and come out
hotter.
I am going to change the layout and have the tubes vertical just to see hwat the difference is, if any.
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chrsgrain
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| posted on 8/6/09 at 11:14 AM |
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The temperature difference is interesting, but doesn't really matter - what matters is the volume of air being transfered through and therefore
heated.
Imagine a system where 1 cubic cm of air was heated to 100 degrees, it still wouldn't appreciably warm a room (say 50 cubic metres as a
minimum), wheras something kicking out several cubic metres of air a minute at 20 degrees would be useful.
I don't think you'll get enough airflow to have appreciable heating effect I'm afraid..... 
Chris
Spoing! - the sound of an irony meter breaking...
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emsfactory
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| posted on 8/6/09 at 12:28 PM |
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good point. I have now stuck a computer fan in the back to blow some air through.
not sure what volume they do but I am getting air blowing out at 44-47 degrees at the minute. Input is 16.
I think I am going to have to start measuring the volume of the room and working out how much air has to be moved to heat it. Then work out if a
heater could feasably be built to do this. Without being the size of the garage itself!
Painting the frame and repairing the rot is on the list!
 
heater in window
[Edited on 8/6/09 by emsfactory]
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DarrenW
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| posted on 8/6/09 at 12:41 PM |
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Well done on the heater. Sounds interesting. Ive often wondered if fitting small fans to the bottom of radiators would improve the convection, noise
might be a limiting factor though.
Ref rot - car body filler can make a decent temp repair. Not sure if the work involved in any repair is worth it against the cost of replacing
sometimes though, except that your labour will be free.
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emsfactory
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| posted on 8/6/09 at 12:54 PM |
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Its really just the ledge that has rotted. I wouldn't bother trying to save it, i'll jusp pull it out and fit a new one. Eventually.
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MikeRJ
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| posted on 8/6/09 at 12:55 PM |
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quote:
Originally posted by emsfactory
good point. I have now stuck a computer fan in the back to blow some air through.
Now you need a solar panel to power the fan
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emsfactory
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| posted on 8/6/09 at 01:45 PM |
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I have moved the fan to pull through the top rather than blow in the bottom. Think that is working better.
The sun has moved quite high now so not hitting very well.
Still was creeping over 20 when I left it.
Anyone know how much air those fans move?
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[Edited on 8/6/09 by emsfactory]
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emsfactory
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| posted on 8/6/09 at 01:54 PM |
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Found a website saying one of these fans should move 13 od cubic feet per minute. About 0.36 cubic meter per minute.
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Vindi_andy
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| posted on 8/6/09 at 01:56 PM |
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remember if the airflow is directly on the thermometer there will be some cooling effect
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