The little vents above the door windows

I have a stupid question,what are the little vents above the doors for. Also I tried out the mattress and I think it 's great. I have a bad back, caused me to retire, and I sleep well.

 

If I remember correctly, the air vents supply enough air to keep one person alive with everything else closed. You don't want the teardrop to be too air tight. Personally, I always leave the vent and windows open just a smidgen regardless of how cold it is.

 

The vents serve a couple of purposes...

One is to reduce the amount of moisture/condensation build up in the cabin.

The other is so you can shut the doors easily. The cabin is well sealed and closing the doors is difficult unless there is a vent to reduce the pressure in the cabin.

Although the vents do aid in fresh air exchange, they are not meant to replace cracking a window or roof vent to keep a supply of fresh air circulating in the cabin.