UKC

Hi I have been asked to build a campervan  for someone and I do have a fair bit of knowledge in building one but the build I have been asked to do doesn't have gas. The customer wants electric only so my question is can anyone suggest a electric or non gas  system  that heats your van ( blown air) and also warms your water for a shower etc.

Thanks

Cheepo Chinese diesel heater.

A diesel heater would sort out the heating. There are water heaters that use the output of the standard diesel heaters but I can't really comment on how well they work.

An electric plinth heater would be ideal for heating the van - have seen others use these as they're small and can be tucked somewhere out the way.

Water I've seen done with immersion heater and pump that sit in the water?

The van will need to be permanently on electric hook-up to do any kind of heating without burning some kind of fuel. If it's not gas then it's going to be diesel, as above.

If they want to use it away from electrical hookups battery capacity could become a problem if using electric. For heating the van a diesel heater would be the best option. Not sure if you can get diesel water heaters though. If staying solely on campsites with electricity then electric is probably easier, assuming you're already planning on having mains voltage in the van.

I did once consider a hot water system using the engine to heat the water. Basically use a heat exchanger (e.g. salvaged from an old boiler) plumbed into the engine's cooling system. This would likely be too much head for the cooling pump at low revs so you'd have to replace that with an electric cooling pump (there are companies that make these). The heated water is then stored in a dewer/vacuum bottle - you can get e.g. 10ltr tanks easily enough (all the examples I found were listed as cryogenic sperm sample storage tanks!). I did some back of the envelope calculations and this should give water warm enough to shower at the end of the day if you'd driven long enough in the morning (can't remember the exact numbers). The problem is it depends on you having run the engine recently, which if you're bumming around from crag to crag might not be an issue. It's complicated and a lot of effort though with a lot to potentially go wrong, so I never bothered.

I found this thingie when looking earlier. It is basically a heat exchanger running off the diesel heater.

https://www.bobilvans.co.uk/howitworks

I haven't heard of them for vans but boats quite often have calorifiers which do exactly as you describe and take waste heat from the engine.

If it's going to be hooked up to the mains then this isn't really a problem as there are many electrical options available for hot water and blown air. If it's off grid then these will mostly be non-starters due to power consumption and battery capacity. 

Diesel would be the best option after gas: something like the Truma D6 does hot air and water but not cheap, or a Wallas XC for blown hot air and a cooking hob in one unit which runs off the van diesel tank.

Perhaps a stand alone diesel heater would do the job and they can decide if they actually need running hot water from the tap?

Fitted a few calorific boat system ones, the tank is fairly big though.For heating worthless. All the major diesel heater brands do hot water as well as heating, there's a lot to be said for going to water-based heating anyway, blown air is a bit annoying a lot of the time.

The electric went off in my campervan the other week when I put a portable fan heater on. On investigation I discovered that the RCD had burnt out. It’s in a locker under our bed (occupied!).

PLEASE have a look at my picture (in my gallery). It’s truly shocking.

Rcd did not trip, mcb did not trip. It melted the top of the box and scorched one of the bed struts.

Upshot was cause was arcing through a loose connection.

Reason I’m posting?

Make sure you check electrical connections in your van.

If converting make sure you use stranded cable.

240v circuits in vans are subject to more vibration than house circuits.

PLEASE CHECK!,

240v circuits should also be installed by a qualified electrician, 12v can be done by a competent person.

Truma d6 is probably the best option but it's spendy. 

If the customer wants electric because the van will be hooked up to a supply then there's no problem. I'd counsel convective heating as it's silent. A small van is very easily heated that way.

Otherwise - surely gas gives cheaper options and can also be used for cooking? Seems odd to specify no gas. Refillable LPG a good idea if being used abroad where UK style cylinders are unavailable.

Many electric hook ups won’t provide sufficient amps to operate an electric heater. You will just trip the circuit breaker in the hook up. What is the aversion to gas? An underslung LPG tank can be the solution to some of the concerns over gas in a van.

For my van I had an underslung LPG tank fitted (only part of the conversion I didn’t do myself). A Truma heater provides blown air and hot water brilliantly, but at some cost.

Almost none in my experience! A 6amp one will power a 700w convector (most have different heat settings). 6 amps will theoretically power 1440 watts. Only place I encountered this was Cortina, and the only thing that would run was the fridge. But then it wasn't cold! The microwave kept tripping it.
Some sites I've been on have been 10amp, the rest 16. In any case the client seems to have specified electric only, and we don't know if that means off grid.

Odd, I’ve used plenty and never had a problem running a fan heater and induction hob at the same time.

Diesel heater or wood-burning stove are basically your only options.

You can't heat with electricity without being connected to the mains, it just isn't realistic.

Americans do it all the time, probably a bit of a hassle fitting a 20kW generator in a T4 though!

+1 for the blown air diesel heater.

I fitted a Chinese clone last winter, very good. Fitting is a learning experience if you haven't done it before. I took me a day, would be half a day 2nd time around.

Lots of support available online for fitting and fault finding. These things are cheaper than spares for an erber, webasto or similar. 

One should be aware that the OP's requirement was for heating AND hot water.

There are plenty of combined air/water heaters available including Chinese ones but mostly they are intended for vehicle integrated heating, while they are heating with air they are also heating the vehicles own circuit (the engine block) and you can't stop the water heating. This is good for some applications but rubbish is all you want is hot water for a shower or washing up. We always fitted two seperate units on boats as the requirements for each are different.

Ah, yeah, ok, I wasn't really considering using a generator. I guess it's fine for a giant RV but I was rather assuming that when the OP said "campervan", this indicated a small van rather than "motorhome" which would be a behemoth. Honestly the smell, noise and extra expense and hassel of having a generator sound like a terrible idea to me but I guess it works for others.

The truma one heats air and water independently + the e model has integrated electric heaters for hook up use.

Also incredibly inefficient converting fuel to electricity then converting that to heat when you can just convert fuel directly to heat.

They do indeed but unless something has changed the Truma Combi series is only gas/220V electric which isn't being discussed as the customer has eliminated gas as an option.

It's probably cheaper to install a gas tank, air heater and water heater but this is the diesel heater I'm talking about.

https://www.leisureshopdirect.com/gas/caravan-gas-water-heater/truma-combi-...

Interesting, they must have a cunning diverter system to stop the water overheating when it's in dual mode which has always been the stumbling block. With gas it's easy enough to just have a seperate burner but with diesel this is a bit complicated. The Wallas one runs through a heating coil in a seperate tank which is easier to cope with but keeping a direct system below 60°C isn't so easy.