Are you looking at buying a kiln but not sure what size will work best for you? We got your back.
In this article, we will look at picking a suitable size kiln to fit your needs, The actual space you need to operate different types of kilns, and a consideration that is often overlooked, how much kilns weigh.
Let’s get started.
What Size Kiln Do I Need?
It can be confusing when you first ask yourself what size kiln you need. After all, kilns are measured in different ways.
Their internal capacity can vary even if they have the same external measurements. And beyond this, different types of kilns can require different amounts of space.
How Are Kilns Measured?
Kilns are generally listed according to the capacity of their firing chambers. That is the size of the box that holds the pottery to be fired and where the work of maturing your clay actually takes place. For most kilns, this will be expressed in one of three ways.
- The capacity of the chamber is given in cubic feet.
- The diameter of the chamber and its depth for round kilns.
- The width, depth, and height of square or rectangular chambers.
This can create an issue if you are trying to make direct comparisons, but a little math can help clear the fog.
If you are given the diameter and depth of a round kiln, divide the diameter in half, multiply this number by 3.14, and then multiply the result by itself. Take that number and multiply it by the depth, and you will have gotten the capacity of a kiln in square feet.
For square or rectangular kilns, the math is even easier width x height x depth gives you the total capacity.
A fly in the pudding can be that many kilns are oval, hexagon, or other shapes. In those cases, our best advice is to use google or contact the manufacturer for information.
Required Operating Area
One other thing to consider when trying to determine what size kiln to look for is how much room you have and how the space is laid out.
The majority of kiln manufacturers recommend a foot and a half of free space around the kiln for airflow and safety purposes. There are other factors, though, that you may need to take into consideration.
Top loading kilns and clam shells
Top loading kilns and clamshell kilns require open space above them to have for the lid to be raised. We, as a rule, discourage people from placing anything above a kiln, but in smaller shops, it may be necessary. Be sure that you have sufficient clearance for your kiln lid to swing up to its completely open position.
Front loading kiln
A front-loading kiln, on the other hand, requires an open area in front of it to allow the door to be swung out of the way for the loading and unloading of wares and kiln furniture.
Remember that for all kilns, it is not just the room needed to open and close them that needs to be considered. You should have adequate space to move freely without risking coming in contact with hot kiln parts, and no combustible materials should be at risk of making contact.
Kiln Sizes by Type and Brand
Kilns come in a huge variety of sizes, from tabletop models that are suitable for cup and saucer size projects to behemoths that can mature large quantities of wares in a single firing.
In this section, we will break down the most common sizes of kilns available by their types and throw in our top picks by brand in each category.
Electric kilns are by far the largest category we will look at. They are most popular with potters, from novices to master craftsmen, and are produced by the largest number of companies.
Their biggest advantages are controllability, convenience, and the repeatability of the results they deliver. They are ideal for beginner potters as they are easy to learn with and, when coupled with modern programmable electronic controllers, are almost foolproof.
As you would imagine, being so popular, they come in a huge variety of sizes and subtypes. You will see electric kilns that are suitable for glass fusing, siring stoneware, earthenware, and even porcelain. There are even many hybrid electric kilns that can be multi-purpose.
You will see electric kilns in top-loading, front-loading, clamshell designs, and even tophat kilns are now often electric.
A large electric kiln, for our purposes, is any kiln with a capacity over seven cubic feet or a diameter that exceeds 25 inches.
Large electric kilns are most often seen in commercial shops, but many home potters who throw rather than build also find them great to own. Throwing is faster than building, so these potters tend to produce more wares.
When paired with an appropriate set of kiln furniture, they can hold a surprisingly large quantity of wares at a time, but they are less efficient if you don’t produce enough pottery to fill them before firing.
If you are a slow builder or someone who can’t wait till they have a full load before firing, they might not be the best choice for you.
Our Choices in electric top-loading larger kilns
Skutt KM Series Kilnmaster Automatic Kiln KM-1227-3
Skutt kilns are widely considered some of the best on the market, and the KM (Kln Master) series is their top-of-the-line.
At 28.5 inches in diameter and 27 inches deep, the KM-1227-3 holds a massive ten cubic feet of pottery. It is a 240-Volt kiln, rated at 40 amperes. This makes it suitable for home installations as well as being used in commercial shops. It is capable of reaching maximum firing temperatures in the Cone 10 range, so neither capacity nor temperature ranges are an issue.
If you want even more bells and whistles, then the same kiln is available in the KMT line as the KMT-1227-3, which features a touch screen controller, wi-fi compatible app that allows you to monitor and program the kiln with a smartphone, and many other features.
Skutt offers many other large kiln models in both their Km and KMT lines, but this is our choice for delivering the most bang for your buck without having to completely rewire your building or take out a second mortgage.
Amaco Excel Kiln with Select Fire
Another line of kilns with many models that fall into the large kiln category is the Excell Line from Amaco. Marketed as having the “most advanced kiln control system ever.” These kilns greatly shorten the learning curve for newbie clay workers and provide master posters with the fine control of the firing process it takes to create fine works of art.
The largest of this line provides a capacity of ten cubic feet inside the firing chamber. This gives you plenty of room to fire large urns or multiple smaller pieces with the use of kiln furniture.
While all the larger kilns from Amaco are very well built and more than worth their cost, pay attention when placing an order for one of these beauties as some models are designed for Cone 10 firing while others top out at Cone 8, and some have maximum firing temperatures only in the Cone 5 range.
A couple of the key features of these kilns include having a backup timer in case of controller malfunction and being able to choose fast, medium or slow firing sequences. This last option allows the adjusting of firing programs that are adjustable to different lead times and dwell periods. A handy feature when working with some of the more exotic glazes on the market.
Our Choices in electric front-loading larger kilns
Front-loading kilns tend to be a little more expensive than top-loading kilns, but they offer much more convenience when it comes to loading and unloading. They do, however, require more clearance in front of them to allow the door to swing freely.
Out top choices for large front loading kilns include.
Olympic Kilns Model FL8E
With eight cubic feet of space and availability in a 240-volt model, the Model – FL8E 240 from Olympic KIlns is our top choice when you need a large kiln and want the ease of using a front-loading kiln.
It is a true Cone 10 kiln and can be had with a large variety of customizable options, including;
- Your choice of controllers
- Solid state relays for reliability
- An automatic door shut off for safety
- Shelf rack for convenience
- Castors to make it easier to move.
This is far from being a bargain basement model, but you get what you pay for. We recommend ordering with original equipment kiln shelves, which come with a 5-pound bag of kiln wash to help get you started.
One of the most advanced kilns on the market, you will never suffer buyer’s regret with an Olympic Kiln.
Paragon Dragon Series
The Dragon Series from paragon Kilns are as legendary as their namesake. They are pricy by anyone’s standards but what you get for your money is an industrial-grade kiln that will serve you a lifetime.
With nine cubic feet of chamber space, you can fire large sculptures with ease or a huge number of smaller pieces all at once. These are true Cone 10 kilns that include such features as;
- A door hung on a heavy ¾-inch steel rod using sealed bearings
- Four-inch kiln walls consisting of three-inch firebrick backed by one-inch ceramic fiber blocks
- Double spring-loaded door latches for a sure seal.
To be honest, the only reason that the Paragon Dragon isn’t our top choice is that its rugged construction would be wasted in the majority of pottery shops and schools.
Medium-sized electric kilns are the size that most potters have in their home shops, and you will find them in many commercial pottery studios. They naturally occupy less space than large kilns and though they don’t hold as many wares at once, are much more efficient for firing smaller numbers of pieces.
Many consider them the perfect kiln size. They provide sufficient space to allow the firing of most of the largest pieces that any potter is likely to ever produce and yet are not so large that the average hobby potter will need months to fill for an efficient firing.
In these times of rising energy prices, the cost difference between operating a full medium-sized kiln and a partially loaded large-size kiln is even leading some larger pottery shops and schools to downsize.
To most crafters, a medium size kiln has a capacity of at least four cubic feet but less than the seven cubic feet that are at the bottom of the large kilns category.
Our top pick In a Medium-sized top loader
Amaco Excel 22″ Deep Select Fire Kilns
We love the Amaco Excell 22 because it perfectly fits its intended purpose of making loading and unloading easier for younger potters and those that are vertically challenged. Built with a deeper chamber but lower sides, it is easier to reach over into for loading and unloading.
Beyond this obvious advantage, these kilns come standard with a spring-assisted lid lifter, an easy-to breakdown and reassemble modular design and reversible slabs. Of course, they are Cone 10 capable, or they wouldn’t be listed here.
These kilns actually come in a variety of sizes ranging from 2.9 to 8.1 cubic feet, which spreads them across the full range of kiln size needs. In our opinion, though, the best of the lot is the 5.2 cubic feet models that are ideal for home pottery studios or small pottery shops.
All these kilns are available in 240-volt, so installation is not a major issue and is ideal where space is limited, but high quality is a priority.