A kiln vent is the accessory people skip first and regret longest. It is not a comfort item and it is not about heat. It is about what comes out of the clay while the kiln is climbing, where that goes, and how long your elements last. Here is the case for venting, the three kinds of venting we sell, and how to tell which one your kiln actually takes.
The short answer
- Electric kiln, indoors or in an attached garage? You want a downdraft vent. The Orton VentMaster is the one nearly every brand sells — $785.
- Gas kiln fired indoors? A downdraft vent will not do it. You need an overhead hood and a flue. Olympic vent hoods run $1,795.46 to $2,249.14.
- Glass only, fusing and slumping? You are usually flash-venting the lid, not ducting fumes outside. A flash arm is $111.28.
- Kiln outdoors under cover, nobody nearby? You may genuinely not need one. Read the section below before you spend.
All prices are our prices as of October 2026.
What actually comes out of a kiln
Clay is not inert on the way up. Bisque firing in particular drives off everything the clay body brought with it — organic matter, carbonates, sulphur compounds, water that was chemically locked into the clay. Glazes add their own list. None of that disappears. It leaves the chamber and goes somewhere.
L&L Kilns, who have been building electric kilns since 1958, put the list plainly in their own firing cautions: carbon monoxide, sulfur oxides, hydrogen fluoride and metal vapors, all of which they describe as potentially very toxic. Their instruction is not subtle either — ventilation, they say, must be to the outside.
Princeton University's Environmental Health and Safety guidance for ceramics studios goes further on the specifics. Chlorine, fluorine, sulfur oxides, nitrogen oxides and ozone are all described as highly toxic by inhalation, with long-term exposure at low levels linked to chronic bronchitis and emphysema. Fluorine exposure is associated with bone and teeth problems. Metal fumes generated at high temperature — lead and cadmium among them — are called out separately. Carbon monoxide gets its own warning: highly toxic by inhalation, capable of causing oxygen starvation, and announcing itself with an intense frontal headache rather than a smell.
That last detail is the one worth sitting with. Several of these have no useful smell at the concentrations that matter. "I would notice" is not a ventilation plan.
The part that is about money, not health
There is a second argument that lands harder with people who fire in a detached shed and are not worried about themselves. Those same fumes corrode your kiln from the inside.
L&L is explicit that kiln fumes and similar environmental conditions cause severe corrosion, and that good venting reduces the problem. They single out wax in particular: wax vapors and combustion byproducts coat the heating elements, which accelerates corrosion and brings on premature failure. If you wax-resist, you are plating your elements every firing.
Elements are not a cheap consumable. A full set for a mid-size kiln runs into the hundreds, and the labour to change them is real. A vent that extends element life by even a third has paid for itself over the life of the kiln. Orton make a related claim for their own system — that it helps increase element life, and that pulling fresh air through the chamber keeps enough oxygen present for glaze colours to develop properly rather than going muddy in a reduction pocket.
Orton also claim the moving air evens out the chamber and softens hot and cold spots. We would file that under "nice if true" rather than "the reason to buy" — but it is their stated position and it is consistent with how downdraft venting works.
The three kinds of venting, and which kiln takes which
These are not competing products. They solve different problems, for different kinds of kiln, and buying the wrong one is the most common venting mistake we see.
| Downdraft vent | Overhead vent hood | Flash arm / lid vent | |
|---|---|---|---|
| For | Electric kilns | Gas kilns, updraft and downdraft | Glass kilns |
| What it moves | Fumes out of the chamber | Combustion exhaust and heat off the top of the kiln | Heat out of the chamber, fast, on purpose |
| How | Fan under the kiln pulls air down through the chamber and ducts it outside | Canopy over the kiln captures the plume and sends it up a flue | Props the lid a set distance to dump heat at a chosen point in the schedule |
| Needs a flue? | 4 in duct to an outside wall | 10 in double-walled pipe through wall or ceiling | No |
| Our price | $785 | $1,795.46 – $2,249.14 | $111.28 |
| Ships | Parcel | Freight, around 200 lbs, crated separately | Parcel, 1 lb |
Downdraft venting, and the VentMaster specifically
A downdraft vent holds the kiln under slight negative pressure while it fires. A small fan sits below or beside the kiln, connected by a short hose to a collection cup under a hole drilled in the kiln floor. Fumes are pulled down and out of the chamber, ducted to an outside wall, and a small amount of fresh air is drawn in behind them through holes in the lid.
Orton received the original patent for downdraft venting of electric kilns in 1988, and the VentMaster is their current system. It is the one you will meet most often, for reasons we will come to.
Specifications
| Airflow | 73 CFM |
| Electrical | 115V, 60 Hz, 1.1 amp — or 208–240V, 50/60 Hz, 0.5 amp |
| Weight | 10 lb |
| Hose supplied | 3 ft of 2 in high-temperature hose, two clamps |
| Make-up air | Not required — normal room conditions replenish the air |
| Effect on firing time | None |
| Second kiln | Supported with the Expansion Kit |
| Maker | The Edward Orton Jr. Ceramic Foundation |
A note on that 1.1 amp figure: it is small, but it is not nothing, and it has to come from somewhere that is not the kiln's own circuit. If you are already at the limit of what your panel will give you, read our kiln electrical requirements guide before you plan the install.
What is in the box, and what is not
In the box: the blower housing with a 6 ft power cord and an in-line on/off switch, a cast collection cup with an adjustable-height foot and a high-temperature gasket, 3 ft of 2 in hose with two clamps, a 1/4 in drill bit, a 3 in stud, sample cones, two booklets and the printed manual with hole-placement diagrams.
Not in the box, and this is the part that catches people: the duct run from the fan to the outside wall. That is ordinary 4 in flexible aluminium dryer duct and a 4 in termination cap, and you will pay less for it at a hardware store than we could ship it to you for. We would rather tell you that than quietly let you discover it on install day. Budget maybe $25 to $40 locally.
Also not included: the drilling, the mounting and any electrical work. There is no drilling template, only diagrams in the manual.
The add-ons, and when you actually need them
- Expansion Kit — $288.90. A second collection cup and hose. Two uses: running a second electric kiln off the same fan, or adding the second cup that Orton specifies on larger chambers. Oval kilns and chambers over roughly 12 cubic feet are the usual two-cup cases.
- Hose Extension Kit — $80.64 for 3 ft, $95.00 for 4 ft. Only needed when the fan cannot sit close to the kiln. The 3 ft supplied in the box covers most installations.
Why you will see this exact vent under five different brand names
Shop around for a kiln vent and you will find an Olympic vent, an Evenheat vent, a Jen-Ken vent and a Paragon vent. Open the boxes and you will find the same Orton VentMaster in all of them, at four or five different prices.
This is not a scandal — it is how the category works. Orton holds the patent and builds the unit; the kiln manufacturers resell it under their own brand because a kiln dealer naturally wants to sell you a vent alongside the kiln. The part numbers give it away: the "Evenheat" vent is catalogued by Evenheat themselves as the Evenheat Orton Vent Master.
We mention it because it changes what you should be comparing. There is no performance difference to agonise over between brands, because there is no difference. What varies is price, what ships in the box, and whether whoever sold it to you will help you work out hole placement for your particular kiln.
We sell it as what it is — an Orton part, under Orton's name. If you find the identical unit cheaper from another authorised dealer, send us the delivered price and our price match applies.
Gas kilns are a different problem entirely
If you fire gas indoors, a downdraft vent does not solve your problem and should not be sold to you as though it does. A gas kiln is a combustion appliance. It consumes oxygen from the room and produces a substantial exhaust plume, and that plume needs a canopy hood over the kiln and a flue out of the building.
Olympic build both stainless and galvanized hoods for updraft and downdraft gas kilns. The square designs carry a 10 in opening at the top for non-flammable double-walled exhaust piping. Updraft hoods mount roughly 36 in above the kiln's top porthole: the 18 in and 23 in models measure 36 in × 36 in, the 28 in is 40 in × 40 in, and downdraft hoods are 48 in × 48 in.
| Hood | Size | Our price |
|---|---|---|
| 18 in & 23 in updraft | 36 × 36 in | $1,795.46 |
| 28 in updraft | 40 × 40 in | $1,965.59 |
| Downdraft, galvanized | 48 × 48 in | $1,995.55 |
| Downdraft, stainless | 48 × 48 in | $2,249.14 |
Two practical points. Hoods crate separately from the kiln and move by freight at around 200 lbs, so factor that into both the budget and the delivery plan. And on downdraft gas kilns the mounting frame is built into the kiln rather than supplied with the hood.
Olympic do not publish whether exhaust pipe ships with the hood, so we do not promise it either. Ask us and we will confirm with the factory before you order.
Glass kilns: venting heat, not fumes
Glass is the odd one out. Fusing and slumping schedules do not release the same load of organics and sulphur that a bisque firing does, so fume extraction is much less of an issue. What glass artists need is the opposite capability: a way to dump heat quickly and deliberately at a specific point in the schedule, usually to arrest a fuse or crash-cool to the annealing range.
That is what flash venting is, and it is normally done by propping the lid a measured distance. Olympic's flash arm is a metal arm that mounts on the kiln and is notched for 2 in and 4 in lid openings, so the prop is repeatable rather than improvised with a kiln post. It is $111.28 and weighs a pound.
If glass firing schedules are new to you, our glass fusing temperature guide covers where flash venting fits into slump, tack and full fuse.
One caveat: plenty of people fire glass and ceramics in the same kiln. If that is you, you are a ceramics firer for venting purposes and the downdraft argument applies.
What a vent does not do
We would rather set expectations here than field the disappointed call later.
It does not cool the room. A downdraft vent removes fumes from inside the kiln. The kiln still radiates heat through its walls exactly as it did before. If your garage hits 100°F during a glaze firing, it will still hit 100°F with a vent fitted. That is a question about room ventilation and kiln placement, not about this product.
It does not make an unsuitable room suitable. A vent is local exhaust at the source. It is not a licence to fire in a sealed closet, a bedroom, or a space where people sleep. Manufacturer guidance is consistent that the kiln room itself needs ventilation as well.
It does not cover salt, soda or raku. Those processes are in a different category and the standard guidance is to do them outdoors. Salt glazing produces hydrogen chloride; raku's reduction step produces smoke and carbon monoxide by design.
Propping the lid is not a substitute. It is common practice for the early part of a bisque, and it does help moisture and organics escape. But L&L list what you are exposing yourself to when you do it without a downdraft vent: heat, live electricity, fumes and the risk of cracking the lid.
Which should you buy
Electric kiln in an attached garage, basement or spare room
Buy the VentMaster. This is the clearest case there is. You are firing inside the building envelope, the fumes have nowhere to go, and the fix is $785 plus about $30 of dryer duct. Add the hose extension only if the fan cannot sit within 3 ft of the kiln.
Electric kiln in a detached shed or outbuilding
Still worth it, for the element-life argument more than the health one — though you do still have to go in there and open the kiln. If budget is genuinely tight this is the scenario where deferring is defensible. Fire with the door open and do not linger during the burn-out stage.
Two electric kilns side by side
One VentMaster plus the Expansion Kit — $1,073.90 together — rather than two complete systems. They need to sit close enough for the hose run, so tell us the layout and we will check it before you order.
A classroom or institutional studio
Vent from day one and put it on the same purchase order as the kiln, because a second requisition is a second approval and student work waits in the meantime. We take purchase orders and will quote before your funding is approved — see our commercial quotes page, and our guide to kilns for schools and classrooms for the wider budget picture.
Gas kiln indoors
An Olympic hood and a proper flue, sized to your kiln. Talk to us first — the hood has to match the kiln and the building, and this is not a part to guess at.
Glass only
A flash arm at $111.28 is almost certainly all you need.
Frequently asked questions
Do I really need a kiln vent?
If the kiln is anywhere you spend time — a garage you work in, a basement, a spare room, a classroom — then yes, seriously consider one. Bisque firing in particular drives off organics and sulphur compounds. An open window is not a vent system, and several of the gases involved have no useful warning smell.
Will a kiln vent cool down my studio?
No. It removes fumes from inside the kiln, not heat from the room. The kiln radiates exactly as much heat into the space as it did before. Room cooling is a separate problem with separate solutions.
Does venting make my firings take longer?
No. Orton rate the VentMaster as having no effect on firing time, and no make-up air provision is required — normal room conditions replenish what the fan pulls through.
Can one vent handle two kilns?
Yes, with the Expansion Kit, as long as the two kilns sit close enough together for the hose run. The same Expansion Kit also supplies the second collection cup that Orton specify on larger chambers, so if you have one big oval kiln rather than two small ones, you may still need it.
Will it fit my kiln?
Almost certainly — it is the same unit that Olympic, Jen-Ken, Evenheat and Paragon all sell for their electric kilns. What varies is hole placement and whether your kiln arrived with the vent hole already drilled. Send us the model and we will confirm before you order.
Can I install it myself?
Many people do. You are drilling a hole in the kiln floor to a diagram, mounting the fan, and running 4 in duct to an outside wall. If the electrical side or the wall penetration is beyond what you want to take on, that part is a short job for an electrician or a handyman — and worth getting right.
What does it cost all in?
$785 for the system, roughly $25 to $40 locally for duct and a termination cap, plus whatever installation help you need. If you are running two kilns, add $288.90 for the Expansion Kit.
Still not sure?
Tell us your kiln model and where it lives — a garage, a basement, a classroom, a detached shed — and we will tell you what venting it actually needs, including whether you need a system at all. We would rather talk you out of a part than sell you the wrong one.
We ship kiln vents at flat-rate freight, we take purchase orders from schools and institutions, we price match other authorised dealers, and we do not collect sales tax outside Georgia. Get in touch or call or text (470) 264-3563.
Working out the rest of your setup at the same time? Our firing checklist builds a parts list from your specific kiln model, and everything you need to start firing ceramics covers the full picture — shelves, posts, wash, cones and venting together.