A well-equipped recreation vehicle is easy to spot. It has two refrigerator ventilation grilles on the outside.
Physically speaking, cold is the absence of heat, so to get something cool you have to remove the heat. A refrigerator releases this heat at the back, and the heat must be able to escape to prevent heat building up and reducing the refrigerators effectiveness. A ventilation system from Dometic is designed to permit service and maintenance, for example cleaning the exhaust duct, without requiring removal of the refrigerator.
Your new vehicle will probably come with this system already installed. If you‘re retrofitting, you‘ll need to fit the ventilation grilles in the outside skin of the vehicle above and below the refrigerator. The upper grille allows heated air to escape, while the lower grille admits cooler air from the outside to the rear of the refrigerator.