Product review: Kuuma knows how to keep a Low Profile

Below is my product review of the new Kuuma Low Profile wood burning sauna stove.

Tower, Minnesota, USA, May 2024. It was a cool rainy spring morning. Golfers call it a “wash out” day. Puddles everywhere, and each one absorbing the constant barrage of raindrops, swelling larger as the day drenches on. And we sauna enthusiasts call these “great days.” Free from guilty burdens like grass cutting, these are days when we measure time as lead ups to round one, and then every moment when we are done with sauna.

I shook off my rain jacket as Garrett Lamppa escorted me into the conference room. On the table sat a large cardboard box. “You know my Dad’s design as well as anybody. The firebox. That we don’t mess with. Anything around the firebox, well, we can design and build around that.” And then Garrett pulls away the cardboard box, to reveal a stripped down Kuuma. A cube of a firebox with the familiar looking steel tight door. No ash pan. No heat shields or rock tray.

“What should we try?”

Well, enter Jeff Pyzyk into the story. I thought I was a sauna madman, being a 3-4 day a week regular, but Jeff, on the other hand, rarely misses a day. What’s more, Jeff is part dragon, part human. And Jeff invested in his first Kuuma in 2018. A Classic medium with no ash pan. Jeff is no stranger to scooping out ash every few saunas, and had been asking for a new Kuuma also without the ash pan but taking away that dead space by creating a shorter stove, a low profile.

“Let’s build Jeff a Low Profile” was our unanimous response.

So, the fine folks at Lamppa Manufacturing built two Low Profile prototypes. And I tested mine for over a year. And here is my review:

To put things in context, I have been running the Kuuma Classic since 1990. Like so many heavy use sauna enthusiasts dotting the shorelines and at hunting shacks and backyards in places like Northern Minnesota, Alaska, New England, many wouldn’t think about messing with the Classic design. But i’m here to tell you that the Low Profile Kuuma works with minimal tradeoff.

Honoring tradition, embracing innovation

Keeping the firebox identical the the Classic stove is one way to keep a Low Profile, and yet Lamppa Manufacturing spent two months testing and tuning the best height for the firebox to sit above the floor. Good airflow and not too much direct heat to the floor below, and keeping the profile low, with no wasted space underneath the stove.

It is not easy to begin altering the Classic heat design dating back decades. What Classic Kuuma users understand is the stove’s perfectly tuned mix of the Jazz Trio of Heat Transfer. The heat in the hot room embodies radiant (all over), conductive (direct), and convective air movement through the stove heat shields, helping create the “wall of heat” akin to Phil Spector’s “Wall of Sound.”*

The Low Profile rock surround sacrifices some convection for more conduction. And there again, Lamppa Manufacturing invested months testing different depths of rock surrounds.

Testing the Kuuma Low Profile

Frankly, I didn’t want to do it. It’s easy to come attached to our sauna stoves. I am a product of cognitive bias as much as any heavy sauna user. We become partial to our heat source like we do with our favorite winter jacket or baseball glove. But for sure I’d test the Kuuma Low Profile!

No Ash Pan. Because of the efficient, clean burn, I only empty the Classic Kuuma ash tray about every 8-10 saunas. So, getting used to no ash pan in my Low Profile was not that much of an adjustment, or compromise. What did take me some “tinkering” is how to light a Kuuma stove without the “cheat” of opening the ash pan door.

For the Low Profile Kumma, the upside down fire technique worked great for me. Full length logs in parallel at the bottom, a few wrist thick logs at the top, and a crumpled piece of newspaper nested amongst a handful of kindling. To help get the kindling ignited and the fire rocking, I found success keeping the stove door open just a crack for the first couple of minutes. I recognize that this technique is very much against Daryl’s “built for safety” ethos, so I share this tip with some reservation.

Heat up times

Having used a Classic Kuuma for decades, I can pretty much bank on how much wood (4 sticks in summer, 5 in winter) and heat up times (45 minutes in summer, 1 hour in winter) for my sauna action. For the Low Profile, I’ve experienced an extra 15-20 minutes in heat up time vs. the Kuuma Classic. Intuitively, this makes sense. An extra 100 lbs. of rock absorb heat. More conductive, less convection.

The Low Profile does take a bit longer to heat the hot room than the Classic. And the reason makes sense. More conduction, less radiant and convective heat transfer. By surrounding the sides and front with rock, the Low Profile’s heat energy is directed to the rocks.

There are no solutions. There are only trade-offs.”

― Thomas Sowell, A Conflict of Visions: Ideological Origins of Political Struggles

We do get nice air movement through the back of the stove, where the classic heat shield design is maintained. I found myself needing a solid hour to get my sauna up to “serving temperature.” With a full firebox of firewood, I would return to the sauna an hour later and be met with temperatures under 150°f. No so with the Classic. Here, given the same conditions and amount of firewood in my Classic Kuuma, my hot room temps would be at least 20°f. warmer.

With the Low Profile, I found myself “riding up” round one to be more enjoyable. With so much rock mass So, i’d say an extra 15-20 minutes. All the Kuuma fireboxes are engineered to completely control the burn rate. The stove door is built with a gasket that seals tightly. The 1 1/2″ inch thick firebrick creates a furnace style burning chamber.

Rock mass

As we know, rocks only matter if they get hot. Matter of fact, though it may look compelling on an Instagram photo, excess rock capacity surrounding a firebox can actually have a diminishing return to heat production and steam performance. In the case of the Kuuma Low Profile, after about 45 minutes, my testing of water placement on the rocks is met with a lot of “psssssssssssst” everywhere. On every rock. For a bit more spicy steam, I will hit water atop the Low Profile. For even softer löyly, I will gently pour water along the left or right side of the Low Profile. This technique allows for steam to happen down the rock sides of the stove.

In either case, through all my testing, no matter where I throw water, all the steam comes from the rocks, not the metal of the stove. And bonus: no water hits the floor. Complete vaporization of water.

Law of Löyly complaint

The Kuuma Low Profile sits 26″ off the floor. With the ash pan the classic design of the original Kuuma sits 36″ off the floor. And anyone clicking around the sauna social medias has surely read about the horrors of having ones feet below the stones while sitting on the top bench. Well, the Low Bench Brigade can rest easy with the Kuuma Low Profile. For a real world testimonial, please check Jeff’s conversion from Classic Kuuma to Low Profile defying the impossibility of obeying the “Law of Löyly” within a seven foot tall sauna.

No toggling between the Law of Löyly and the Bleacher Effect with the Kuuma Low Profile.

Others’ input

Now that the Low Profile is in general circulation, others have been using the stove for a few months now.

It’s been a learning experience, no doubt. I love it. The steam is intense but soft at the same time.

-Chris H., Minnesota

The lower stove height offers a better bench to stove height ratio (mostly to satisfy loyly Poliisi). This is the closest thing to a big rectangular-top savusauna Kiuas where you can pour löyly in different spots and on different rocks for different frequencies of steam, (like a Caribbean musician playing a steel drum).

You can use it almost like a single-fired Kiuas because the stones stay hot for hours (as George Jones and Tammy Wynette would sing, “even after the fire is gone”.) The rock sides diffuse and reflect radiant heat into multiple directions vs. nominal diffusion and linear reflection with flat steel sides. The Kuuma Low Profile is a 9.5 out of ten because nothing is perfect!

– Jeff P., Wisconsin

Kuuma is the name to go with, if you’re building a sauna in Minnesota, and quite frankly beyond. Once you’re up and running, it is pulling air up and through. No backdrafting.

-Justin E., New Zealand

Summary

Those familiar with the Kuuma sauna stove know all about its even heat, and clean burning efficiency. by burning dry clean wood, like ash, the small tradeoff of shoveling out the fire chamber without an ash pan is easy to overcome. If law of löyly is an important consideration, then the Kuuma Low Profile offers you compliance and performance in one 26″ tall powerful package.

Let’s check in with Justin who has paired a Kuuma Low Profile with his sauna tent (soon to be on a container ship off to New Zealand, where he plans to upcycle his Low Profile into a brick and mortar build at his New Zealand home):