Our last trip out in the Troll, we were at Sandringham CC, the opposite side to the door,
was facing the bitter wind and we got condensation along the midline just behind the
backrest cushions.
I bent up some cardboard to space the cushion off the wall, and surprise warmer air
came up from under the bench where the warm air pipes had been going strong.
I know that there are some good insulations about http://caravanchronicles.com/2014/03/29/all-wrapped-up/
There are slotted tubes in the Truma warm air ducting range http://www.caravanaccessories4u.co.uk/pr...-outlet-vent-wl
https://dealernew.truma.com/_anweisungen...40000_53300.pdf
And to round it off some under mattress anti condensation netting http://www.shipshapebedding.co.uk/Dry-Ma...CFeXLtAodzTgAQQ

We're on our 4th Eriba and this is the first without the blown air system. I just assumed it would be there when we ordered it but no, nada!
The woodwork has holes where the fat tubing would go and there were a couple of the outlets already fitted.
I didn't think it would be a great loss but we really miss the warmer air in the bathroom.
We have also had the slight condensation behind the back rests occasionally so I am seriously considering installing the Truma blower and some of the tubing.
It looks like a simple job and only involves 12v electrics but it ain't cheap!

Warn air in the bathroom?????????????? Go up to the facilities block

Seconded

and thirded

Those slotted connectors look worth a punt https://dealernew.truma.com/_anweisungen...40000_53300.pdf