This item from Truma is take fresh from another compartment- filter it to the next compartment.

2 metre Flexible Air Conditioning Intake Coupling by Truma

The felxible room air intake allows the Saphir aircon to be installed into an area that is sealed off from the interior (false floor, outside locker, toolbox, rear storage area), this prevents contaminated air from being drawn in.

Great to use a return air intake for diesel and gas heating also.