# Airconditioning systems for larger motorhomes



## Vennwood (Feb 4, 2007)

I have a question for all you knowledgeable guys and dealers.

Why is it that manufacturers such as Hymer, N+B, Dethleffs, Burstner, Carthago et al all offer the Truma Saphir Vario as either standard or optional equipment in their top end motorhomes? The Truma literature for the Vario clearly states that this unit is only suitable for MH's up to 5.5mtrs long. Does this lead to poor operation or is this Truma acting cautiously? 

Members with these units fitted - are they effective in hot weather?
Or do they just take the edge off the heat?

Just curious......


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## Ozzyjohn (Sep 3, 2007)

I too would be keen to hear of real world experiences with these units.

Ours has one fitted. It seemed to work reasonably well during the warm days we had at half term (late May) in Bristol. Hopefully not the most stretching task that it will be able to cope with. We've only had the bus for 3 months so no chance to test it in really hot weather yet. 

I was a bit concerned that it would be very noisy in use, but didn't find that to be the case in practise. 

Hopefully, I will be able to give a more complete answer later in the year. 

Regards,
John


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## GOVER (May 1, 2005)

I have a 8.7m German motorhome which is 3.2 m tall - massive by any calculation. We stay every summer on the beach at St Tropez without shade. We have Trauma underfloor air conditioning 2700w which works faultlessly despite stingy French mains 7 amp supply. 

It has 3 ducts, one to the rear bedroom, which we can screen off and this remains very cool and pleasant ( sized 2m x 3m x 1.75m). 

In the front living area we have one duct to the front of the cab and another over the kitchen. The front struggles to remain comfortable. I have considered various options to supplement the front area including a roof unit or a portable window unit but the electricity supply does not allow an extra system.

I had a Hymer S Class with a powerful electrolux roof unit - it was very loud and too intrusive to sleep. It also could not cope with these conditions in any way. Hence I specified the above when we upgraded the van.

N.B. I have always used internal silver screens on all roof lights, front side windows and screen to try and reduce incoming heat.

To improve underfloor cooling system an ordinary fan helps to improve circulation of the cooled air. 

I hope this is of advice is of help.

Gover


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## Bubblehead (Mar 5, 2007)

Hi

We have a Dometic / easy cool CA 2500 which is an excellent bit of kit. It will cool the whole van down to 'shiver temp' in about 45 minutes. We did this on a 6 amp EHU. The best bit about it is that you cant hear it outside until your within about 2 m of the van and then only if its a very quite site. It has a 12v option, but we didnt go for it as I didnt want to damage the bats to much

Andy


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## Vennwood (Feb 4, 2007)

GOVER said:


> I have a 8.7m German motorhome which is 3.2 m tall - massive by any calculation. We stay every summer on the beach at St Tropez without shade. We have Trauma underfloor air conditioning 2700w which works faultlessly despite stingy French mains 7 amp supply.
> 
> It has 3 ducts, one to the rear bedroom, which we can screen off and this remains very cool and pleasant ( sized 2m x 3m x 1.75m).
> 
> ...


Hi Gover,

thanks for the feedback. Just curious to know which unit you have when you say 2700W as the largest Truma (Compact) pushes out 2500W - is yours boosted in any way?
Was it fitted as standard?

Coolauto told me that for our Flair the Truma Vario would be no use but the comfort or Dometic HB2500 was the answer.


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## Ozzyjohn (Sep 3, 2007)

> The Truma literature for the Vario clearly states that this unit is only suitable for MH's up to 5.5mtrs long.


Curiosity aroused, I had to have a look and I couldn't find this?

The only reference that I could find to 5.5 mtrs was relating to the Truma Saphir Compact - see Truma Saphir Compact

The Truma Saphir Vario - see Vario doesn't seem to have any suggested maximum length.

Or am I missing something?

Regards,
John

ps our van is just shy of 9 mtrs long and about 3.3 mtrs tall - but the double floor and rear garage reduce the volume to be cooled....


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## Vennwood (Feb 4, 2007)

Ozzyjohn said:


> > The Truma literature for the Vario clearly states that this unit is only suitable for MH's up to 5.5mtrs long.
> 
> 
> Curiosity aroused, I had to have a look and I couldn't find this?
> ...


Hi John,

I've seen it somewhere on the Truma site, under questions/installation etc. Can't find it myself now but I was looking at it earlier today - honest.

I will find the link and send it to you.

in the meantime here is a link from their dealers, scroll down to see suitability

http://cart.coolauto-onlineshop.co.uk/index.php?p=product&id=13&parent=46


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## Rapide561 (Oct 1, 2005)

*Aircon*

Hi

A bit off topic, but I have a Dometic B2200 aircon unit and I find it is very good at keeping the van cool, but not so good at getting the van cool. Basically, on a warm day, I will run the aircon on a low and quiet setting all day rather than blast it later on high setting. Once the van is hot, it seems to stay hot come hell or high water.

Russell


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## Ozzyjohn (Sep 3, 2007)

Morning Trev,

No worries, I do that all the time!

On checking again while packing the van late last night, I see that ours is actually the Saphir Comfort IR model - rated at 2400W.

The whole question of rating them by van length must be a bit questionable though, surely? Ours is quite long (certainly by European standards) at 8.9 mtrs - but quite a bit of the volume within that isn't being cooled (the garage, and the cab area when the sliding door at the front is closed). It should really be related to volume, but I guess that isn't quite so easy to sell as a concept - I would need to think to work out the internal volume of our van. 

I'll keep my fingers crossed for a heat wave so that I can give more comment based on actual performance. 

Regards,
John


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## Vennwood (Feb 4, 2007)

Hi John,

Here is the link to a volume calculator that CoolAuto and Truma use to calculate volume. It looks a bit crude when using it for motorhomes but I guess it may be near enough

http://www.aircon4u.net/www.aircon4u.net/air-conditioning-cooling-calculator.php


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## Vennwood (Feb 4, 2007)

Just had 2 emails back from Truma about the Vario.

1st makes no mention of my question as to why the Vario is fitted in N+B, Hymer etc. when theyare over 5 mtrs but does say that there is no upgrades for manufacturers, but say the Comfort would be best suited for larger vehicles

2nd email in response to my original question with the 5 word answer -
"The unit should still perform"

So I guess the Vario is ok in large MH's even though they say its not recommended

odd......


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