Dedicated Heating / Hydronics / Diesel heating thread

Geo.Lander

Active member
Insulation is the key.

I put loads of thought into Raditors behind seat backs, 7 program timers day timers, room thermostats and tank thermostats etc.

The reality is that we have never really used any if it to its full ability.

Because we have good insulation we rarely use the heating. If its needed we simply turn it on for about 20 minutes by which time we are probably sitting in our underwear. It will then stay hot all night.

We don't have duvets or heavy bedding, we simply sleep under a very thin fleece sheet and have never been cold.

I have 2 matrix fan heaters and several finned radiators. If I was fitting it again today I wouldn't bother with the radiators and just go with the matrix fan heaters , they put out more than enough.

The lowest we have been is minus 25 at 5000m and it has all performed fine and the inside tempreture overnight was perfect.

What can mess these heaters about is poor diesel , such as Bolivian, but that's whole different issue

Neil
If the floor heating proves to be too complicated maybe I just need to simplify things a bit, do you think you would have settled for less radiators doing this over? I was thinking one next to the bed, towel bathroom radiator and one in the elevated seating floor like in the picture below... also floor heating adds 16mm too (for the very low profile kits), it does not seem like much but I am keeping the inside height at 200cm and I am 194cm so it adds up.. I am hoping to truck's height will be around 350cm or lower.. Not easy to achieve with a 4 point subframe, solar, bush rails and suspension lift I am finding out..

120222000_3316934768427218_2296342168187480848_n.jpeg
 
As far as vehicle height, the covers for 2-way vent/fans are higher than solar panels. In my opinion they’re indispensable. I’ve added 2 from the original in the bathroom. Bathroom vent is 127mm.
The newer ones maybe 90-100mm. My camper is 1.95m high inside. With 395 tires and normal load and AV HD rear springs, total height is 3.57m. Which can be lowered to 3.52m with beadlocks and CTIS, don’t forget about tire deflation trick.
I am going to get some Al bars to protect panels that don’t stick up higher than current height.
You’re right, with 5cm higher cabin you will have trouble coming up with 12cm to stay below 3.5.
What size tires again?
 
That lowers you by ~40mm relative to 395s, at road pressure, but aggressive deflation isn’t as safe as with 20s. The UK Unimog owners manual shows road inflation pressures for 385s, but only shows off-road deflation guidelines for 20s and 24s (agricultural types).
You get the most mm towards the bottom pressures; it’s nonlinear.
 

Geo.Lander

Active member
That lowers you by ~40mm relative to 395s, at road pressure, but aggressive deflation isn’t as safe as with 20s. The UK Unimog owners manual shows road inflation pressures for 385s, but only shows off-road deflation guidelines for 20s and 24s (agricultural types).
You get the most mm towards the bottom pressures; it’s nonlinear.
We'll have a homebrew STIS (semi-automatic) system for tire pressures (hopefully). We might end up getting a set of 20s for desert adventures but for now it's 22.5 because of the studded winter tire choices mainly. But I'm really digressing away from heating systems now 😀
 

Alloy

Well-known member
Insulation is the key.

I put loads of thought into Raditors behind seat backs, 7 program timers day timers, room thermostats and tank thermostats etc.

The reality is that we have never really used any if it to its full ability.

Because we have good insulation we rarely use the heating. If its needed we simply turn it on for about 20 minutes by which time we are probably sitting in our underwear. It will then stay hot all night.

We don't have duvets or heavy bedding, we simply sleep under a very thin fleece sheet and have never been cold.

I have 2 matrix fan heaters and several finned radiators. If I was fitting it again today I wouldn't bother with the radiators and just go with the matrix fan heaters , they put out more than enough.

The lowest we have been is minus 25 at 5000m and it has all performed fine and the inside tempreture overnight was perfect.

What can mess these heaters about is poor diesel , such as Bolivian, but that's whole different issue

Neil
Interesting how our uses determine things🙂.

We stay at one location for a 7-10 days and want limit starting (energy needed to warm the engine & starter batteries) an engine in the cold. My choice would be a passive (no fans) system that solar "may" keep up with.
 

Neil

Observer
Alloy

Ordinarily we would not be heating the engine . This would only happen just prior to starting before leaving.

I'm.not sure what you mean by passive heating. The fans in the heater matrix uses very little electrical energy. I think less than1 amp per hour. The furnace does use some electrical power on start up and shut down but when running it uses very little. I'm sure a reasonable Solar Array will keep up with it easily

Neil
 

Alloy

Well-known member
Alloy

Ordinarily we would not be heating the engine . This would only happen just prior to starting before leaving.

I'm.not sure what you mean by passive heating. The fans in the heater matrix uses very little electrical energy. I think less than1 amp per hour. The furnace does use some electrical power on start up and shut down but when running it uses very little. I'm sure a reasonable Solar Array will keep up with it easily

Neil
By passive I mean using as little battery power as possible. This week we were set up in the trees for 7days with rain/snow. With the bathroom heat for drying (2.5A) , ghost loads, charging devices, water pump, inside/outside lighting the 1.3Kw solar on the roof couldn't keep up with 6hrs of daylight. Once I set up 3 portable panels the (2.3Kw now) system was keeping up but we needed to use the Starlink (6-8A) so the batteries had to be charged off the engine. If it was below -15C the egine would be heated beforehand which uses another 150Ah.
 

grizzlyj

Tea pot tester
Our one careful previous owner Mog camper had a 5KW hydronic Eberspacher which could happily get you past 35degC inside with snow out :) The insulation was a bit rubbish too, single pane roof lights. That was with a calorifier and an air blown heater matrix with four outlets at floor level (noisy and dried your eyes when used to that excess). When you had just had a shower, the burner kicked off again to heat the calorifier, the air blown from the vents became cold, not nice on your wet skin as you towelled off! And on arrival somewhere, the 5KW would get you warm but not instantly. I seem to remember the calorifier is supposed to be the first thing downstream from the burner since you want that hottest, but once that has sucked the heat from the coolant your rads will then be chilled for a time. Perhaps a bigger burner than the calcs would suggest just to minimse the time you have with less than ideal heat? But we could have a fully hot calorifier 20 minutes after stopping so never a big deal.

That Mog camper had an overcab bed which made it probably too tall (but the height itself never became an actual issue). This leant itself to a false floor whose thickness varied from maybe 75mm to 500mm and storage and water tanks under. The hot pipes from the burner loop ran round within this which mostly gave a nice gentle floor heat as it heated the air in the gap.

There was a thread here where someone worked out that with the maximum temperature you could tolerate from the floor, and the area remaining once the furniture had been allowed for, it didn't give you enough output to maintain a sufficient cabin temperature. Maybe that is a also an insulation thing though? And time.

As I've bored you all with before, our Mog had the correct Eberspacher parts for connecting into it's coolant system similar to as described by some here but it didn't work so wasn't used. It was similar to what Joe's sounds like but was useless. The only few things that went wrong with that chassis was where someone had changed what Merc made. We went with a Mog because of it's reputation, so i came to the conclusion that buying into that but then fiddling with it was a little contradictory, KISS and leave well alone would be my view now. If you can get the bits that the manufacturer uses to plumb a pre heat system and exactly replicate that then I would go with that, but that system won't include heating your camper box. Changing the original according to a third party I would try not to do. Preheating an engine designed to start from cold at minus I can't remember what is required to reduce a bit of smoke? Well, quite a lot of smoke really, best leave early :)

We did have some issues with that old Eberspacher to begin with. For instance the fan inside the burner supposedly had the same part number for 12v or 24v and we were sent the wrong one which oversped and broke. The three screws sealing the burner chamber, undone every time it needs the soot cleaning out, are soft ally and easily deformed if set fast from repeated heat cycles. Finding and fixing a problem yourself may require changing a few bits to find the fault. On that basis we now have a second whole spare burner on our newer old camper.
 

Toby3

Member
hi, are heating / hot water systems also used for shower / kitchen sink or have people got that done separately? Not sure whether need more of power shower set up, ie electrical element in power shower heating water at that point rather than needing a hot water system for it
 

VerMonsterRV

Gotta Be Nuts
hi, are heating / hot water systems also used for shower / kitchen sink or have people got that done separately? Not sure whether need more of power shower set up, ie electrical element in power shower heating water at that point rather than needing a hot water system for it
We have a marine 6 gallon water heater with an internal coolant loop. Our hydronic heating system is plumbed through it. Shower/kitchen and bathroom sinks are hot water plumbed to this tank. I have also replaced the 110v heating element with a 12v, so on sunny days we can heat water using solar power. The only thing left to add is heating domestic water and the habitat with engine heat, just got to let other projects settle a bit before I tackle that.
 

Toby3

Member
HI, trying to figure out the plumbing solution. AV have suggested a Surejust Calorifier, I think this is similar to a Truma but anybody have any experience of them? Also any suggestions around building in filters into the plumbing system, looking at initial slimline filter going into the fresh water tank, won't provide completely safe water but limited on space, then looking at a reverse osmosis filter after it comes out of the fresh water tank. Again any experience with this or anyone used something different?
 
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