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rear heating pipes to make a heat exchanger
Posted: 06 Aug 2008, 08:22
by kimbobill
1986 2.1 caravelle morphing into a camper.
I am thinking of using the rear heater pipes to give me hot water!
I just wondered if anyone has installed a water tank, removed the heater box and used the feed and return pipes via a copper heat exchanger coil (home made) to heat the water and then a pumped feed off?
This obviously will only work when the engine is running so if the above works the next step was to run a home made solar heat exchanger on the roof into the same tank.
what do you think? good idea? Or have I got too much time on my hands to think up stupid ideas
Posted: 06 Aug 2008, 14:23
by CovKid
Sounds good idea tho could be expensive in terms of trying to put parts together. Depends how much you really need hot water I guess but lets face it, you can put a kettle on which doesn't take too long. If you're really into making use of the energy available then why not. I'm always experimenting with ideas to reduce battery load (LEDs etc) but for the few times I actually want hot water, I'm not sure I'd bother.
Posted: 06 Aug 2008, 14:27
by Titus A Duxass
Sounds good, but, as CovKid mentioned, put the kettle on.
We have one of those Camp Showers, I slap it on the roof and we use the water for washing(-up).
Posted: 06 Aug 2008, 14:31
by R0B
yes..
have I got too much time on my hands to think up stupid ideas
Posted: 06 Aug 2008, 15:01
by 1664
The camper I hired in new Zealand had a system like that. It is a good idea but mostly it goes to waste as when you park up after a long drive you don't fancy washing up. The tank was insulated mind so it stayed hot for a while and was handy for a quick body wash. Took up a fair bit of room though.....
Re: rear heating pipes to make a heat exchanger
Posted: 06 Aug 2008, 17:01
by Mr Bean
kimbobill wrote:1986 2.1 caravelle morphing into a camper.
This obviously will only work when the engine is running so if the above works the next step was to run a home made solar heat exchanger on the roof into the same tank.
what do you think? good idea? Or have I got too much time on my hands to think up stupid ideas
Of course there are many other much worse things for idle brains or hands even for that matter to do. So dreaming up hairbrained schemes os OK by me. One can make a very efficient calorifier by using different diameter copper tubes concentrically using Odd ended "T" junctions. this way you can pass hot "engine" water down the jacket while the drinking water down the centre faorm a thermosyphonic loop into your properly insulated hot water tank. I use a similar system for additional water cooling on my boat.
Cheers
Ken
(Keep that brain and hands busy won't you!)
Posted: 07 Aug 2008, 07:44
by kimbobill
Thanks for the responses. I never thought about when the water would be required, Doh! I wanted the hot water for a shower when we come off the beach, unless I drive around for 30 minutes it's on with the solar heat exchanger idea
I was thinking of using 8mm copper zig zagged back and forth between the roof stengthening bars and feed it in through the rear vents via a hole in the roof. I really don't want to increase the hight by much as I can get into anywhere ie multi story car parks.
someone surgested using black rubber/plastic type hose as it's a lot more flexible and I can get a more runs over the roof! what do you think.
The main sections of heat exchanger would be boxed in ali and covered in perspex probably have to change that every couple of years
Looking forward to your thoughts
Posted: 07 Aug 2008, 08:43
by Titus A Duxass
Black Irrigation Pipe is the thing to use.
On the beaches of Rimini (and probably elsewhere) you can see little shower huts.
On the roof of these huts are discs of irrigation pipe formed by winding a spiral of the piping.
The discs are about a metre in diameter and are constructed from approx. 25 mm diameter piping.
You could easily adapt this technique for the VW roof shape, I don't know if the UK sun is upto the job though.
Posted: 07 Aug 2008, 08:44
by camper
I have done some think like this but the tank is used for heating waste vegi oil for a biofuel conversion.The tank has a capacity of 50 ltrs and has two looped mild steel tubes feed by hot engine coolent fitted to the tank.The tank was coated with a protected fuel sealent to stop any reaction between the oil and steel.Its fitted under the floor between the inner chassis rail and outer seal on the near side of the vehicle with flexible hose coolent pipes to it.The tank is filled via screwed brass cap.As i said its used for heating waste vegi oil the outlet has an auxillery lift pump for the fuel to the engine.An alternative to the tank could be a use for a hot water supply simply by running the auxillery pump with water to a internal sink .If you want any picts of the installation i can send via email.
Posted: 07 Aug 2008, 11:02
by kimbobill
I'll look into that Titus sounds good and yes please camper I think my email is available on site but I drop it via pm just in case
Posted: 07 Aug 2008, 19:21
by CovKid
How about a still? With some ingenuity we could all make moonshine
