We put the covers over the two outside vents in colder weather (less than 10deg), take them off when it’s warmer.
I wouldn’t use sealant inside though. We used foam pipe lagging, cut into strips, wedged in around our washing machine at home where there’s a draught because of the air vents in the wall.
We’ve also just turned the MH around in the past.
Yes, strips of foam jammed around the fridge box from the back, (remove the two vents on the outside to gain access) you will probably see great holes where the wind is blowing through, often near floor level. Leave plenty of air flow from bottom vent to the top one & around the black fins, but keep it away from the hot gasses vent tube, when used on gas.
Should an engineer need to remove the fridge unit for any reason in the future, it's still easy to do and not glued in place with silicone. As said, vent covers are good if you are using the van in the colder seasons of the year, it stops things freezing too readily.
Dave
------------- Never argue with an idiot, they will drag you down to their level and beat you on experience.
Mark Twain.
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