The Orton Vent Master removes a small amount of air from the kiln, mixes it with room-temperature air, and vents the air out of the room. The Vent Master removes fumes from the kiln and brings in a small quantity of fresh oxygen.
Removing the fumes eliminates many ceramic defects such as pinholes. The fresh air improves glaze colors.
The Orton Vent Master is called a downdraft vent, because it removes air through the bottom of top-loading kilns. Removing fumes creates a slight negative pressure in the kiln, which prevents fumes from leaking into the room.