Patrick's, Steve's and mine all have Eberspacher hot air cab heaters which just sip Diesel.
On full bore (3.4Kw) they blow out loads of very hot air and use just 0.2l per hour!!
On a low setting it probably only fires up around 10 minutes per hour, so uses proportionally less Diesel.
We tend to use them for 10 minutes before going to bed as that is plenty to get the Carawagon really warm, then switch off until the morning (unless we're winter camping
). If the control/stat is within reach, it's nice to put your arm out of the sleeping bag to switch it on in the morning, then wait a few minutes until its warmed through.
They aren't cheap though - you're looking at around £1400 brand new
I've managed to get two on ebay, complete with pump, exhaust, wiring and stat/controller. The first for Patrick's Carawagon was £125, and the latest for mine was £160.
There are a lot on ebay who say "
not tested as haven't got a car battery" or "
worked when removed" or similar which I would avoid. If someone can't be bothered to connect one and fire it up for half an hour with temporary leads and pipe to a can of Diesel I wouldn't buy it as they can go wrong and are very expensive to fix!
I go for the ones who say "can be seen running" or who post a youtube video of it running, but of course, you pay proportionately more for those
The only thing you've got to watch, especially if leaving them on overnight, is they do take a fair bit of battery power to fire up and run, so you'll need a good leisure battery as well. Something like 8-10A on firing sequence and a couple of amps when running. They also have low voltage cutoff so won't fire up below about 11V, probably because they normally run off the lorry starter battery
Eberspacher and Webasto also produce hot water versions for pre-heating engines or for running 'central heating' in canal boats. You could plumb one of those in with a calorifier and have stored hot water, but again, you run into header tanks etc. for the hot water system then.
I did see a Carawagon with a small catalytic heater (the sort used in caravans) fixed to the front of a cabinet, and that would probably be the cheapest 'safe' way to provide heat.
Of course, the very cheapest way is to put the kettle on 10 minutes before bedtime to fill a hot water bottle. The cooker heats up the vehicle and the hot water bottle keeps you warm in the night
I was doing that early this year when it was cold before I fitted my heater, but I also have a carbon monoxide detector fitted
I think Mick (Jabbawocky) has a Webasto (very similar to the Eberspacher) ready to fit in to his Dormobile, so he might come along with advice on where to fit one in a Dormobile.
Rest assured, if you go to any of our 'winter' gatherings, you'll hear the Eberspachers firing up like jet engines at bedtime
Hope that helps,
Robin.
) had his surface mount socket behind the rear number plate which he hinged at the top 
Must admit if it's cold and I'm camping I do put the gas ring on to warm up for ten minutes.
