Heating Improvement? (1 Viewer)

[Stevewheel]

Hi All, we have a Truma Combi 6E fitted to our small A Class and on both gas and electric it does us very well for both hot water and warmth. However something has been nagging my "this could be better" part of the brain. The warm air is conducted around the van by the ubiquitous flexible cylindrical ducting. Some parts of our van are not double floored so the ducting (shortly after it leaves the boiler) dives through the floor & runs along the underneath of the van before re entering elsewhere and continuing its journey to the various outlets. This happens in a couple of places and in total I suppose about 2 -3 metres of the ducting are exposed to "fresh air" underneath the van. It's clearly intended to be like this since all the pictures in the handbook show it this way but I can't help feeling we'd get a bit more heat out of the system if these external runs were lagged or insulated in some way. Does anyone else have the external ducting thing and have you lagged them/boxed them in in some way? Did it improve the heating/economy? Any thoughts, tips, hints greatly appreciated.

 

[Vanderek]

I lagged my external ducts using something like this ...seems to do the job ...https://www.screwfix.com/p/spiral-wrap-x-50mm-x-7-5m/62194

 

[Speve]

It would certainly be a good idea to lag them, our Exsis is part double floors but all heating ducts are internal even the tanks are heated but no external ducting. Perhaps some foil lagging that you could wrap around and tape on would do the trick.

 

[EuroTrotters]

Hi All, we have a Truma Combi 6E fitted to our small A Class and on both gas and electric it does us very well for both hot water and warmth. However something has been nagging my "this could be better" part of the brain. The warm air is conducted around the van by the ubiquitous flexible cylindrical ducting. Some parts of our van are not double floored so the ducting (shortly after it leaves the boiler) dives through the floor & runs along the underneath of the van before re entering elsewhere and continuing its journey to the various outlets. This happens in a couple of places and in total I suppose about 2 -3 metres of the ducting are exposed to "fresh air" underneath the van. It's clearly intended to be like this since all the pictures in the handbook show it this way but I can't help feeling we'd get a bit more heat out of the system if these external runs were lagged or insulated in some way. Does anyone else have the external ducting thing and have you lagged them/boxed them in in some way? Did it improve the heating/economy? Any thoughts, tips, hints greatly appreciated.

I lagged our A/C Ducting for the similar reasons.

Have you any photos?

 

[Minxy]

Our previous PVC, Autocruise Accent, had ducting that went outside then came back in ... totally stupid idea as it could easily have been kept inside!

I used some foil lagging sheets that I already had with gaffer tape to keep it on - I found it fairly easy to do this as the sheets could be pushed over the top of the lagging, between the pipe and the camper base, which I then taped with one long piece of gaffer along the overlapping join - I suspect this was easier than trying to thread the lagging tape roll round and round the pipe with the 'tight' gaps.

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

Just a thought, while you're under your van check out if any of your water pipes are exposed too ... ours were and had some pipe insulation put on them too!!!

 

[Stevewheel]

Thanks for all the replies so far. Seems I'm not alone and good to here that so many have had the same thoughts on this. Operation "Lag" now firmly in the planning stage I think. I've tried to insert a picture here so folks can see what I mean.

 

[Lenny HB]

Our first van was a Hymer Tramp and the bedroom was quite cold, that had some ducts running outside. I tried lagging them didn't make any difference. I even measured the heating output lagged and unlagged no difference.
The black ducting in your photo is the Truma lagging the heating pipe is inside the black lagged pipe that's why more lagging won't make much odds.
The Combi 6 is as you know 6kw output more than enough heat to heat most size vans, it is the way the heating is distributed that makes the difference.

The Tramp a French bed model had a cold area on the outside wall in the bed area and the mattress was cold on that side despite warm air vents behind a panel beside the bed and the locker door under the bed used to get bad condensation on the alumium frame when the heating was on. The only heating vent in the locker was on the opposite side to the locker and mostly blocked off by stuff in the locker. I took the bedframe out remove all the timber work encasing the heating pipes and fitted a Y junction and a new vent that blew along the outside wall. Result warm bed and no condensation on the locker.

I mention all this to show that with a bit of thought and modification to the system you can probably improve it.

 

[Stevewheel]

Interesting @LennyHB, thank you. Seems there may be more to this than I first thought.

 

[tonyidle]

Where such pipes are 'lagged' it's normally done by slipping the next size up same type of tubing over it. Easy & should work well especially as the tubing has a foil finish inside.

^{_{Subscribers  do not see these advertisements}}

 

[Spriddler]

The Tramp a French bed model had a cold area on the outside wall in the bed area and the mattress was cold on that side despite warm air vents behind a panel beside the bed and the locker door under the bed used to get bad condensation on the alumium frame when the heating was on. The only heating vent in the locker was on the opposite side to the locker and mostly blocked off by stuff in the locker. I took the bedframe out remove all the timber work encasing the heating pipes and fitted a Y junction and a new vent that blew along the outside wall. Result warm bed and no condensation on the locker..

It's hard to believe (or not perhaps) that with all their experience and the considerable cost of a m/h that manufacturers still haven't got their design perfected and rely on owners to improve the installation. Obviously none of the staff have ever spent time in their own products.
My particular bête noir is showers in camp sites and yacht marinas. In so many of them the shower tray or floor tiles are as slippery as a skating rink, they deliver only weak dribble, there are insufficient hooks, nowhere dry to put shoes, the angle of the fixed shower head means that in order to get in the spray area you have to either flatten yourself against the cubicle wall tiles or against the door. The press button only gives about 15 seconds of spray and any shelf is undraining and has a puddle of the previous occupant's soapy water............
I now go into each cubicle and test the shower before I strip off and discover that the one I'm in is barely usable.
I'm sure that the designers or site owners have never tried them.
Grrrrr!

 

[Stevewheel]

@Spriddler - With you all the way there my friend!

 

[Lenny HB]

It's hard to believe (or not perhaps) that with all their experience and the considerable cost of a m/h that manufacturers still haven't got their design perfected and rely on owners to improve the installation. Obviously none of the staff have ever spent time in their own products.

Well at least they improving a bit, my current hymer has valves to turn the blow air heating on/off along side the beds, mind you it doesn't appear to do a lot.
However it will be a miracle the day Dometic mange to produce a fridge that works.

 

[davidathomas42]

Thanks for all the replies so far. Seems I'm not alone and good to here that so many have had the same thoughts on this. Operation "Lag" now firmly in the planning stage I think. I've tried to insert a picture here so folks can see what I mean.

Yup wow that picture is amazing. Amazingly dumb anyone building a heating system would think that's a good idea! Gonna check where my pipes on my Swift go as the bathroom one possibly goes under the floor to outside.

 

[Stevewheel]

@davidathomas32 - Indeed - been doing a bit more research and it seems the phenomenon of routing ducting outside vans is really common. As @LennyHB posted earlier in the thread I have discovered that ours actually run inside similar lengths of larger ducting pipe so they are effectively "double walled". Lenny says that lagging such a set up didn't seem to make much/any difference. Despite Lenny's good advice I'm still tempted to have a closer look as running hot pipes outside a van just seems counter intuitive somehow. I'll get the boiler fired up and running and then see what temperature I can detect on the outside pipe. However, whatever happens, its a good exercise because as Lenny also mentioned I have now discovered a waste pipe that runs outside. The fall on it means that anything freezing in there is unlikely but I still think I'll wrap it for the sake of a couple of lengths of foam.

^{_{Subscribers  do not see these advertisements}}

 

[jaygee]

Check that the ducting out of the boiler is pushed fully home, only a push fit and can come detached

 

[Hettie's Crew]

On our previous Motorhome (Bessacar E450) the heater was centrally mounted, so the piping to the front seating area went underneath and the piping to the rear went through the bed box. There was no insulation on either, not double skinned and looked just like the flexible ducting you have on a tumble dryer but smaller. The result was cold in the cab area with no discernible heat coming from the vents and hot under the bed with a little coming out of the vents in the rear. I would have insulated both had I kept it, but my plan was to box in the area where the heating pipes are filled with loft insulation.

 

[peterc10]

Get yourself a double floor model. All the services run between the floors. And then add Alde heating rather than Truma. It is the difference between having a fan heater and having real central heating.

 

[chaser]

It's hard to believe (or not perhaps) that with all their experience and the considerable cost of a m/h that manufacturers still haven't got their design perfected and rely on owners to improve the installation. Obviously none of the staff have ever spent time in their own products.
My particular bête noir is showers in camp sites and yacht marinas. In so many of them the shower tray or floor tiles are as slippery as a skating rink, they deliver only weak dribble, there are insufficient hooks, nowhere dry to put shoes, the angle of the fixed shower head means that in order to get in the spray area you have to either flatten yourself against the cubicle wall tiles or against the door. The press button only gives about 15 seconds of spray and any shelf is undraining and has a puddle of the previous occupant's soapy water............
I now go into each cubicle and test the shower before I strip off and discover that the one I'm in is barely usable.
I'm sure that the designers or site owners have never tried them.
Grrrrr!

That's why they put showers in motorhomes

 

[Spriddler]

That's why they put showers in motorhomes

Yes, that's fine if you've a spacious modern bathroom/shower with rigid walls but I don't enjoy the straight jacket embrace of a cold claggy plastic shrink-wrap curtain. Furthermore, discovering that my elbow has displaced the curtain and soaked the brand new and only loo roll is an unwelcome start to my day.

^{_{Subscribers  do not see these advertisements}}

 

[chaser]

Yes, that's fine if you've a spacious modern bathroom/shower with rigid walls but I don't enjoy the straight jacket embrace of a cold claggy plastic shrink-wrap curtain. Furthermore, discovering that my elbow has displaced the curtain and soaked the brand new and only loo roll is an unwelcome start to my day.

Even that's got to be better than your version of site showers that I have to believe having never had the pleasure of useing them.

 

[Minxy]

Interesting @LennyHB, thank you. Seems there may be more to this than I first thought.

Lenny may not have noticed a difference with the MHs he had but we certainly DID find it made a lot of difference - we had the outer black 'skin' layer with the inner actual heater ducting running through it but putting the insulation on it too really did mean that the camper warmed up much quicker than without it. Another thing to bear in mind is that if the heating isn't on, external ducting will definitely allow the cooler air 'seep' into the MH via the heating vents so always close them on a night when you turn it off ... unless of course you don't mind being a penguin!!!

 

[JockandRita]

Having an older model A Class Hymer on the Fiat 230 series cab, like others, I experienced a cold spot from the left side foot well, especially when driving. When pitched up, the cab area is always the coldest, so I installed another Truma fan and controller, just before the last vent from the boiler, behind the driver's seat (LHD). In winter time, this extra (and very efficient) two way fan makes all the difference to the temperature of the cab floor area, but hardly makes any difference to the power consumption. A couple of other FUN members have carried out the same modification to their large A Class MHs.

On the subject of the outer lagged ducting, I too wondered about heat loss through those, when we first got the MH, and as with @Lenny HB, I found there to be very little heat loss from the lagged trunking. It is more robust than the internal lagging, is foil lined, and mastic sealed at the exit and entry points of the under flooring. We don't experience any draughts, as a result of that.

HTH,

Jock.

 

[Spriddler]

Even that's got to be better than your version of site showers that I have to believe having never had the pleasure of useing them.

Yes, the m/home's 'phone box' shower is better than some site showers, however one doesn't have any choice after spending several days on a stripped out racing yacht or a with motorbike and tent.

 

[Lenny HB]

Even that's got to be better than your version of site showers that I have to believe having never had the pleasure of useing them.

When buying a new Motorhome the shower is one of the most important bits to us, current van can just about get two of us in the shower a sensible design.

^{_{Subscribers  do not see these advertisements}}

 

[Spriddler]

When buying a new Motorhome the shower is one of the most important bits to us, current van can just about get two of us in the shower a sensible design.

Quite so; and it's vital to have one that dries out before the wife gets back from the toilet block

 

[jdk62]

Get yourself a double floor model. All the services run between the floors. And then add Alde heating rather than Truma. It is the difference between having a fan heater and having real central heating.

but lagging is quite a bit cheaper.....

 

[peterc10]

but lagging is quite a bit cheaper.....

Yep ........ why didn't I think of that rather than changing the motorhome ........

 

[Musicboy]

If you could trace where that feed was going it may be that it's not really required ... &:ya could shut that off &:have the air blown where it's required more .
I've diverted all my pipes to the areas which may be vulnerable to frost & to where the living area is . Works great & I've been able to remove @ 2 metres of pipes & connectors ...
plus .... The air flow is more powerful .
See.... "what have you done in your vsn today "...
Bit of a job but worth it ... I've had vans with the air / heat pipe under the floor & ecposed to ths elements ... both Truma & surprisingly Alde too...
Looks like designers " where did that pipe go"