When watching videos about composting there seams to be two kinds. Those that are made from pallets, and therefore have air gaps and those with solid walls.
According to this video, the correct way to make smell free compost is by having the correct ratio between Nitrogen, Carbon, air, and water. The video shows a bin with solid walls, and here a video where he have a pallet based compost bin.
To produce smell free compost, should the bin have air gaps or not?