This is something I have been looking into and gathering info about for the last couple of years. Our Camper like many of your own ones is constantly evolving into what is ideal for us. Our story is Mum Dad and 7 year old boy that likes to get muddy, here is a quick bit of back ground.
We started off with a tin top 2.1 petrol Caravelle,
Then it got turned into a pop top camper running on LPG,
Then got turned into a hightop,
Then we moved to a Syncro Doka and turned it into a camper with R&R bed etc,
Then bought a Westfalia Syncro 1.9d, then AAZ 1.9 td conversion, then 1.9 TDI AFN conversion.
All great vans in different situations but we have settled with what we have now through what we learned through using the others. I got rid of using gas as a fuel for driving and domestic now and apart from the two rings that doesn't use much of the Westfalia underslung tank per year and the new fridge is a compressor one that runs on 12v and is like your fridge freezer at home. I have 260ah's of power that is fed by a sterling charger always loads and loads of spare gas like I said, 4wd that gets us any place we want to be with front and rear diff locks, stacks of engine power good MPG blahdy blahdy blah...
But like many on here and prompted by a post in General Chat the other day by Andythesweep I hate that we have no hot shower
We have an old black plastic army jerry can water carrier that Sevey kindly gave us a few years ago that holds 20 liters and it gets really warm in hot weather and by using one of those 12v shower pump kit things you can get 7.5 minutes of warm shower. Its good and works well in temperatures above 28*C but if its that hot you dont mind a cool shower if you know what I mean and you can always jump in a lake.
Later this year we are planning a trip to North Africa for a month or two with some mates and it will be in winter. Although it will be a lot warmer than here in Morocco on the way down and on the way up loads of campsites will be closed. Even when we get further south you have high altitudes and we will be getting some pretty cold weather and snow and we want to be self supporting and there is no way that black jerry can is going to get warm
I know you get those black bag showers too but I always remember when Jake (AKA Syncroand101) did a similar trip with Russel and Andrew a few years back and Andrew left his shower bag out ready for a refreashing shower and they took a picture of it with an icicle hanging off the end 
Sooooooo what are my plans? These have been the options running round my head at night when you think about this kind of stuff but I have now settled on the one that will give me more than one use but it hasn't been tested or even made and I don't know anyone who has done it yet or even mentioned it.
Option one,
The good,
Make a thin copper pipe coil and plumb it into the coolant system of the van that dips into the fresh water tank. This way I can fit a valve so that when I am driving along and the engine is hot I can open it and it will heat the water and I can plumb in a submersible pump and shower head.
The bad,
I have a TDI and the engine takes ages to get hot and if we were parked up somewhere for a few days and tried to do it on idle and heat being transferred to the fresh water it would take for ever and I would have to leave the engine running and be annoying. The tank wouldn't stay that hot for very long after we stopped unless I insulated but you have to still run the engine and be annoying.
Option two,
The good,
Get an Eberspacher engine coolant heater and plumb it into the water tank that will heat up the fresh water to get hot water and do the shower thing like option one. Good if you dont want to drink the water.
The bad,
Not so good if you dont want to drink the water.
Option 3 (and final choice)
The good,
Plumb an Eberspacher coolant heater into the vans coolant system and it will heat the vans engine on cold mornings and can be set to turn on the factory heaters on a timer so the windscreen is defrosted and the engine warm. This will also be good of we do an arctic trip in the future as it heats the engine bay before you start the engine and most people who live in the Arctic Circle use them. If our existing air fed Ebber ever plays up when its really really cold on this or on future trips we have a back up heating source (I learned this from the people who build the Unicat). I have found out how to make an inline heat exchanger cheaply so I can run the Eberspacher coolant heater without running the engine and heat water for the shower as I need it once the Eberspacher coolant heater has heated the small amount of water in the engine before the thermostat opens. The heat the shower takes out will hopefully slow down the engines thermostat from opening so soon but this is going to be the interesting bit that I really don't know how it will work. I have found an overland company that sell a heat exchanger for not to stupid money but I am sure I can make one from what I have been picking up over the past couple of years. It would also give the option of hot water at the sink using a mixer style tap and when the engine is hot through normal running temperature I can heat water through the engines coolant system while on the move .
The bad,
Its trial and error and might not work so might have to go back to option 2, or buy the heat exchanger from the overland company I know that has a product that works for this job for a couple of hundred quid or so.
So how much is all this going to cost?
Well the Ebber coolant heaters are cheap compared to the air heaters and are probably less officiant but I have noticed that the newer VW Transporters are fitted with them over the air driven devices,
http://www.ebay.co.uk/itm/Eberspacher-D ... true&rt=nc" onclick="window.open(this.href);return false;
I paid a little bit more for mine through an 80-90 member for the peace of mind that if it did not work I could bitch like hell and get my money back
So thats the price of the heater, plus some rubber pipes and T peaces, a few hose clamps and some tube to make the heat exchanger and a timer if I want to go all out so lets say timer. I have the shower stuff all ready and some wire and connectors will be used that I have.Thanks for sticking with it so far but I have tried to compress a couple of years of thinking into one post. Its going to be trial and error and like I always say I am no expert on these things and I am not trying to give bad advice because I really don't know how this will turn out. If I f**k up putting an Ebber in on this thread then it will be seen and please feel free to join in if you see it can be done better to save me scrapping a perfectly good Ebber and I will follow.
I feel better for that....
Today a box arrived,
I then took the insides out,
Then I spent half an hour going through the Ebber D5w online manual to work out the loom and where stuff goes and crimped a few bits,
My plans are to bench test it this weekend for a few hours to make sure its OK then make the heat exchanger for the shower and see if that works and if not make it bigger. Then when its all working outside the camper over the next few weekends I will fit the unit in the left hand side rear quarter in the engine bay and I am thinking about putting the heat exchanger under the back seat in line with the rear heater matrix.
Wish me luck
Jed
