UK sites with metered electricity

Again your outfit is a MH.

I think in the concept of the thread what unit it is is irrelevant the process and amount of heating required is the same for the same size area. 

We have both caravan and a MH. Both run on exactly the same boiler system.

In winter I do as BB described I put the heating on mix to start off with then once it warms up the gas drops back. 

Overnight I turn the heating down from 22c to 17c and on the lower 900w setting. This keeps the caravan nice and warm, all but the rear bathroom.

The MH has 'silver screens' fitted to the cab in winter so very little heat loss from there. I heat up the MH the same way as the caravan, overnight it is set just the same. 

I do find the MH heating kicks in more overnight.

I have run both on full gas to get things warm and then turned it back to 900w to maintain.

I also carry a fan heater as back up but have used it on occasion when its not worth putting the main heating on but I'd like a bit of warmth. Usually late evening in the shoulder seasons, I use the fan heater as I find it quicker than the main heating unless gas is used. 

Out of interest do you close your inner blinds in the cab as well as putting on the silver screens outside.

I have tried it both ways and I think it is warmer with inner closed and outer on. 

Both of the MHs we've owned have had rear lounges where the heating seems to be concentrated. We do have a vent at the front of the van but its pretty ineffective, by the time the heat travels along the tubs its lost most of its warmth and just about all its power. So the coldest place in the MH is by the cab. 

We've never used silver screens, our previous peugeot cab wasn't well insulated so always chilly. The present mercedes cab is much better but we also used to find our caravans could get chilly too, don't think we'd ever be warm at 900w as previously suggested. We'd be up to 2kw in the colder months in any type of van in the uk. The trouble with boxes on a frame is they leak warm air so the heating has to work quite hard to keep a constant temperature and they have a lot of air vents too.

I would think that insulation plays a part for the same volume though?

Yes but still irrelevant to being a MH or caravan.  Obviously a well insulated vehicle will keep heat in once warmed up better than one that is less insulated same as any building.

If we were to stop using gas in caravans there would be no need for all the holes in the floor that are there in case of a gas escape but let the wind whistle through.  Might save quite a bit of heat.

I would have though a motorhome or campervan with decent cab heating would not need much warming up if any on arriving at a site. Mine certainly does not, I even arrive with hot water because the engine is fitted with a heat exchanger which uses engine heat to drive the Aldi system. I suppose I could warm it up before setting out on a journey but I don't because it does not take long for the cab heating to be effective before assisting the heat exchanger and spreading to the rest of the van.

My motorhomes have had far more effective heating systems than any of my caravans in fact i traded in my first caravan because I wanted a better heating system.

peedee

well I would disagree, there appears to be a difference between insulation in the two which slows down the loss of heat and therefore needs less power for the same volume and warmth? And therefore is relevant in my view. 

MH appear to need, or people like to have them, these insulating screens at the front which a caravan doesn't.

With blown air heating (where air heats up and cools quickly) it's better to have the unit placed centrally where each of the four pipes can be kept as short as possible yet service all corners equally. With ALDE Hot water heating, the heated water which circulates to the radiators retains its heat so boilers and radiators can be placed less strategically.

our Combi is pretty central, and the outlets are numerous (3 in the cab, two in the lounge, one near the door (so being a front lounge van, that's effectively 6 in the habitation area), one in the bathroom, a long pipe that completely surrounds the bed (with multiple smaller outlets) and one in the garage...so plenty of heating points throughout the van, and with all the pipes running under the floor, feet are warm, as are water tanks and batteries..

smaller, cheaper, lighter vans (including ours) probably wouldn't see the benefit of an ALDE system that adds weight, complexity and cost.

we have a double skinned thermal blind that rolls down to cover the windscreen and blinds to all the side windows, but I made some extra thermal sections which fit neatly between the factory blinds and the side windows, creating a very warm cab area.

back to the OP, even if we all insulate our vans to the nth degree, it won't give us a saving if we can't benefit by using less fuel...but the club will.