The overhead Vent-a-Kiln vent is positioned over the kiln with the aid of a counter-weight. As heated air rises from the kiln, the vent pulls it outside through an aluminum duct. This system also helps lower room temperature around the kiln.
The Orton down-draft vent connects directly to the kiln. A small amount of air is pulled from the kiln and mixed with room air. This lowers the temperature of the vented air to a safe level. Small holes drilled in the kiln lid and bottom regulate the amount of air that the vent pulls from the kiln.
Vented Air Volume & Temperature Both vent systems remove air from the kiln room. Open a window or door to replace the air that is vented outside.
Many studios keep the door to the kiln room closed. In this case, you must open a window or install an intake vent so that make-up air can enter the kiln room. Orton KilnVent Volume of Vented Air: 60 - 80 CFM Approx. Duct Temperature: 100°F - 155°F
Vent-A-Kiln Volume of Vented Air: 265 - 500 CFM Approx. Duct Temperature: 90°F - 125°F
Installing the Vent The Vent Exit Point Plan your kiln room to include an exterior wall. The fumes are vented to the outside through a clothes dryer duct. If the kiln room does not have an exterior wall, you will need to run the duct through the ceiling or floor to the outside.
Avoid placing the vent exit near windows. Otherwise the fumes may reenter the room. If you are in a multi-story building, avoid placing the vent exit under upper story windows.
If you cannot avoid placing the vent exit near a window, you can raise the vent above the level of the window. As the warm air is vented outside, it will rise past the window.
The Vent Duct The duct size will depend on the type of vent you are installing. Several kilns can be vented to a single exit duct. The size of the exit duct depends upon the number of kilns vented and the brand of vent.
Duct Length and Width
Orton KilnVent Duct Maximum Length: 60’ with 4 - 90° turns Duct Width: 4"
Orton KilnVent Duct Maximum Length: 60’ with 8 - 45° turns Duct Width: 4"
Vent-A-Kiln Duct Maximum Length: 10’ with 2 - 45° turns* Duct Width: 5” & 6” *20’ if you extend the duct with rigid duct.
It is okay to include vertical lengths of duct, because the warm air rises. Use aluminum flexible duct. Do not use the plastic flexible duct sometimes used on clothes dryers.
Orton KilnVent You can use 4” PVC pipe, provided your building code approves. PVC lasts longer than aluminum duct, especially if you fire clay with a high sulfur content.
Do not connect the PVC directly to the KilnVent. Instead, use several feet of flexible aluminum duct between the vent and the PVC. This prevents vibration of the motor from transferring to the PVC.
Seal all joints with duct tape. When aluminum duct begins to deteriorate, small holes will appear, and you will begin to smell kiln fumes. At that point, replace the duct rather than attempt to repair with duct tape.
If you fire the kiln with the Orton KilnVent turned off or removed for repair, cover the air exit holes in the kiln bottom. Place a kiln shelf over the holes.
Leave the vent on throughout the kiln firing and cooling cycle. Turn the vent off when the kiln is cool enough to unload bare-handed. The vent will help remove moisture during “candling” at the beginning of the firing. The moisture in the duct and motor will dry out as the kiln heats.
When using the Orton KilnVent, leave the kiln’s peephole plugs in place and lid down all the way throughout the firing. The vent operates under negative pressure, which requires that the lid and peepholes are closed.