Sizing a Sauna Heater

A sauna heater is the heart of any traditional sauna, so it’s important to make sure that you have the right one. This means having an appropriate sauna stove with the features and heating method you prefer, but it also means having one that will heat your sauna comfortably and efficiently.

When building saunas, there are often misconceptions that lead people to installing improper stoves, which ultimately ruin the sauna experience. First off, it is never a good idea to use an old wood stove that was intended for home use. It may seem like an efficient hack, but those stoves are not meant to withstand steam, which leads to heavy rusting. Second, never put a barrel stove in your sauna. They burn much too hot, and are prone to catching saunas on fire. The last thing you want in a wooden room is an uncontrollable fire.

Also, when you’re building it’s important to keep your ceiling height around 7 feet. Making your sauna too big makes it more difficult to heat, and forces you to get a larger stove. We’ll go over why in a moment. 

Now that you’re ready for a stove, it’s time to figure out what size you need. Sauna stove sizing is based on the volume of the sauna. Basically, how much space there is from wall to wall and floor to ceiling in your sauna. To calculate volume multiply the width, length, and height together. For example, a sauna that is 6 feet wide, 8 feet long, and has a 7 foot ceiling would have a volume of 336 cubic feet (6 x 8 x 7 = 336).

A rule of thumb is that you’ll need 1 kilowatt of power for every 50 cubic feet. So, our sauna would need a heater that could put out 7 kilowatts of power. It is always better to round up in this case. It’s smarter to keep a stove cooler than to overheat it. 

And that’s that! All sauna stoves will be labeled with either their ability to heat in terms of kilowatt power or the volume of the sauna required. Now it’s time for you to shop around for the stove that you prefer, which you can do here at our website. In our example, the Harvia Legend 150 would be a great wood burning stove for our sauna. 

Of course, if you have any questions or you can’t decide what sauna stove is right for you, feel free to talk with one of our knowledgeable representatives in person or on the phone here at Alaska Stove and Spa.