How to Start a Fire in a Sauna Stove

Obviously, the main goal of any person starting a fire in a sauna stove is to:

• Get the fire started

• Get the sauna hot

However, it’s important to know that when starting a fire for your mobile sauna rental that there is more to a fire than just flames. A good-quality sauna fire requires a few key elements:

Elements of a quality fire

1. Safe and controlled

A well-controlled fire is important for both the longevity of the sauna stove and the safety of the sauna users using the sauna rental.

2. Clean burn

A clean burn is better for the environment and our lungs (and also the least likely to upset the neighbors). We can monitor our fire by looking up at what’s coming out of the chimney. We want to see a clear vapor coming from the chimney. It’s expected to see gray or white smoke (full of particulate matter) coming from the chimney right after starting a fire or adding a log, but for the majority of the sauna session it should be clear.

3. Long-lasting burn

The longer your fire lasts, the fewer logs you need to use. This is better for the environment and the money in your pocket.

So how can we accomplish all of these things? As a sauna host, we have a few tools in our tool belt to check each of these key elements off our list.

Ingredients for a quality fire

1. Seasoned firewood

Even the best chef in the world would struggle to make a high quality meal without high quality ingredients. Similarly, a sauna host can’t create a great fire without great firewood.

Always, always, always use dry, seasoned firewood in your sauna stove.

Seasoned firewood lights easier, burns cleaner, burns hotter, and burns longer than unseasoned firewood.

We want our wood to have around 15-20% moisture content. Why? Moisture causes that gray/white smoke which is not ideal for the environment or our lungs, limits the heat our wood can output, and also causes creosote buildup in the chimney potentially leading to a dangerous fire hazard.

While using wood seasoned for at least 6 months is adequate, we prefer kiln-dried firewood to accomplish this and is what we deliver with all of our mobile sauna rentals. Since it’s dried in a kiln instead of outdoors, not only does it have a low moisture content, but it is also free of bugs, mold, and anything else that you don’t want to be breathing in.

2. An efficient stove

To stick with the cooking analogy – while a great chef may be able to make do with just about any utensils or cookware you give them, the margin for error might be smaller, cook time may increase, and the entire process might require much more attention and focus. The same goes for a sauna stove.

A high-quality sauna stove provides you with all the tools you need to manage the air flow and heat as safely and as simply as possible.

We love and use the Kuuma stove in all of our mobile sauna units for all these reasons. It also definitely helps that when you’re enjoying the heat in your mobile sauna here in Minneapolis, you can be proud to know the stove was hand-crafted locally from just 200 miles north in Tower, MN.

A steel stove perfected and built like a tank for 3 generations, an easy to use air control lever, a roomy fire box to easily fit standard 16” logs, ample room for stones, and the perfect design to maximize heat output. You know you’re getting the quality and attention to detail as opposed to something mass-produced with corner-cutting to maximize profit.

3. Fire building technique

There are countless ways to build a fire, but we’ve found that the upside-down technique is the quickest and lowest-maintenance method to get a fire roaring and the mobile sauna up to temp. Credit to Glenn from Sauna Times on initially turning us on to this method!

How does it work?

It’s simple, but counterintuitive to the traditional down-up method. Place 4-5 medium logs at the base of the firebox and then light your fire with birch bark/newspaper and smaller kindling on top of the logs. The fire will slowly burn down to the logs below. Instead of tinkering with the fire and slowly adding wood, just walk away and return to a beautiful fire and hot sauna. This means more time with your family and friends, and less time tending to a fire during your sauna party.

Why does it work better?

Lighting a fire near the top of the firebox gets airflow traveling through the stove and into the chimney almost immediately. This minimizes backdraft of smoke into your sauna, and quickly gets you into that clear vapor stage of the fire. Instead of immediately exposing your larger logs to flames, it slowly and more evenly heats the logs below before they actually catch fire. This creates a more complete and efficient combustion when they ultimately catch fire, and in turn, more heat and longer lasting logs!

4. Controlling air flow

Fire needs oxygen to grow, but too much oxygen can create an unruly fire that could be dangerous or damage the stove, and too little oxygen could mean your fire won’t be able to adequately heat the hot room.

We advise opening the air lever all the way up until the logs catch fire (about 15 minutes), and then lowering the air lever to about 25% open for the remainder of the sauna session.

Pro tip: While it seems counter-intuitive, a roaring fire doesn’t actually create the most heat in the hot room, as most of the gasses escape out the chimney. A well-controlled, slow burn is the best use of logs and keeps those beautiful gasses in the firebox to heat the hot room.