We have a single door 10cf Norcold refrigerator in a slide. It has 2 vents. We purchased a wireless thermometer set which will monitor both the freezer and the refrigerator. Ours runs within normal specs and interestingly it cycles just like the frost free residential fridge in our garage. The RV fridge is not frost free but the cooling fins in the refrigerator do run through a defrost cycle almost every day so with the wireless thermometer we can see this. We can even set it to alarm when it raises abive a set temp. So if you want some peace of mind, you might go the wireless thermometer route.