Nobody Told Me the Heater Was the Whole Point
I spent years using saunas wrong. Then I started paying attention to what was actually in the room.
The first time I used a sauna that actually changed something in me, I didn’t know what I was sitting next to. I just know the heat felt different.
I’d been in gym saunas before, the cedar-paneled boxes that smell like eucalyptus spray and other people’s towels. They’re fine. You sweat, you leave, you feel vaguely accomplished. I never thought too much about what was generating the heat, or whether it mattered.
Then a friend invited me to his place. He’d built a sauna in a room off his garage, something he spent eight months on, researching obsessively. I expected a shed. What I walked into was something I didn’t have the vocabulary for yet.
The thing standing in the corner
The heater took up more of the room than I expected. It was a floor-standing unit — a tall stone pillar, really, wrapped in steel rings, loaded with a serious amount of rock. My friend called it a “tower heater.” He’d picked it after months of research, landed on one of SAWO’s tower-style units — a Finnish brand that apparently makes heaters the way some people make furniture, with genuine thought about how the thing behaves in a room.
He explained that the pillar design matters because steam doesn’t just billow off the top. It moves from the bottom up, distributing heat through the full height of the room rather than collecting at the ceiling. That detail — something I never would have thought to think about — changed what I understood about why some saunas feel enveloping and others just feel hot.
“I’d been confusing temperature with heat. They’re not the same thing in a sauna. One is a number on a thermometer. The other is something you feel through your whole body.”
We sat in there for forty minutes. My friend threw water on the stones every ten minutes or so — löyly, the Finnish word for the steam ritual that has no direct English equivalent. Each round of steam felt thick and complete, not thin or sharp the way it does when the stones aren’t hot enough or there aren’t enough of them. I left feeling something I can only describe as thoroughly emptied out. In a good way.
· · ·
What I started researching afterward
I went down a rabbit hole that I suspect many people go down after their first genuinely good sauna experience. I started reading about heater design, stone mass, steam character. I started to understand why Finns treat the sauna as a specific, considered practice rather than an amenity.
Get Stephanie Gonzales’s stories in your inbox
Join Medium for free to get updates from this writer.
Finland has more saunas than cars. That stat gets quoted a lot, but what it actually means is that generations of people have been refining exactly what makes a sauna good. They’ve had time. The heater isn’t an afterthought — it’s the architecture the whole experience is built around.
Stone mass, it turns out, is one of the most important factors. More stone means the heat is more stable, more sustained, less prone to spikes when you open the door or throw water. The rocks act as a thermal battery. Smaller heaters with fewer stones tend to run hotter and recover more slowly — they feel aggressive rather than embracing.
Soapstone is a different conversation entirely. It conducts and holds heat in a way that stainless steel simply doesn’t. A few manufacturers make heaters from Finnish soapstone — SAWO’s Cumulus is one of the wall-mounted options I came across, designed specifically for that gentler, more radiant kind of heat rather than the direct blast you get from a steel unit. I haven’t sat in one yet. I want to.
The design argument nobody makes
Here’s something that doesn’t come up enough: a heater is visible. It’s often the most prominent object in the room. And yet most heaters look like appliances — things to hide or ignore.
There are exceptions. Stefan Lindfors, a Finnish designer whose work I’d seen in other contexts, collaborated with SAWO on a series of heaters where the steel casing carries a laser-etched pattern he calls Junglefire. The Heaterking is the large-format version — a tower heater for commercial-scale spaces, but one that looks like it belongs in a room you’d actually want to spend time in. It’s the first time I thought of a sauna heater as something designed to be seen rather than tolerated.
That’s not a trivial observation. When the main object in a room is beautiful, it changes how you relate to the room. A sauna with a heater that someone clearly cared about is a different psychological experience than a sauna with a beige metal box bolted to the wall.
What I actually changed
I don’t have a garage sauna. I live in an apartment and that’s not in the near future. But I started using my gym’s sauna differently — more intentionally, for longer, paying attention to how the heat feels at different times of day when the stones are at different stages of their cycle.
And I started paying attention to the heater. Which, I now realize, I had been completely ignoring for years.
Most gym saunas use wall-mounted units — compact, practical, sized for a room that needs to heat up fast and serve a lot of people. The one at my gym is fine. It does what it’s supposed to do. But it’s not the same as sitting in my friend’s room with a stone pillar radiating heat from the floor up, with enough rock in it to hold steady for an hour of steady löyly.
The difference isn’t price. It’s understanding. Someone had to decide what kind of heat they wanted the room to produce. That decision happened before any wood was cut or wiring was run. The heater is the first decision. Everything else follows from it.
“The Finns have a word for the spirit of the sauna — saunatonttu. It lives in the heater. I think I finally understand what that means.”
I asked my friend what made him choose the heater he did. He said he spent three months on it, reading forums, watching Finnish YouTube videos he could only half-understand, cross-referencing the room dimensions against kW ratings. He treated it the way a serious cook treats their first real knife purchase — not as an accessory, but as the thing everything else depended on.
He was right to. The room is good because the heater is right. That’s not a coincidence.
