Stratification.. a good thing or no? Heat naturally rises, so the upper parts of the sauna naturally want to be hotter than the lower parts. This principle creates layers of temperature. Example:
- Top bench: is where it is hottest (can be 180°F or more).
- Lower bench or floor: is noticeably cooler (often 20–40°F lower).
There’s some talk about stratification NOT being a good thing. Downdraft, cold feet, fans and heaters designed to “equalize” the temperature from top to bottom. Are these examples of attempted solutions to something that isn’t a problem? Let’s consider three aspects inside our hot rooms.
Every body is different
Some have more body mass, and some are hard to notice when they stand sideways. Children are best on the lower benches as their rounds are shorter, and more frequent. And even the same person on different days has more heat tolerance than other days. Be it stress, or fatigue or just wanting to take it easy, the lower bench may welcome us on different days. So, thanks to the jazz trio of heat transfer and multidirectional radiant heat. any body can get its core warm while enjoying sauna on the lower bench.
Commercial saunas understand this. As people pile in for an Aufguss session, many mark their territory with choosing to spread their sitting towel on the lower bench. Others on the middle bench, and the rest file in up top. Stratification, the temperature gradient in a hot room, allows for people to find their own place of heat comfort. Commercial banyas all offer multiple levels of seating. Same situation.
Magical moments of equilibrium
Within a sauna round, sometimes we feel as if we’ve had enough, but maybe our core just isn’t quite there yet. Or, our minds are not quite ready for a cold plunge or avanto (ice water swim). Or, maybe we’re in the middle of a good conversation and we just don’t want to leave. “Wait, let me tell you why I was wearing a pair of boxers on my head when the neighbors showed up.” The cooler temperature on the lower bench, stratification, allow for magical moments of equilibrium.
A welcoming microclimate
As more and more people tap into the holy trinity of good sauna (heat, steam, ventilation), like sipping a good wine, more of us can begin to appreciate the welcoming microclimate that our saunas present to us. When we throw water on the rocks, and the waif of lôyly comes over us, we experience a variable bouquet of heat blending with steam. For many, a sharp blast of lǒyly exudes sisu (strength, fortitude) akin to that addictive feeling of entering ice cold water. The yin to that yang.
For others, löyly is best felt mildly and softly. Stratification (different temperatures) in our saunas give us an opportunity to welcome both lǒyly extremes, and everything in between. Sharper up top. Softer down low. Could anything be more wonderful?
Sure, cold feet on the bench is a major buzz kill. That’s a subject for another day. There is Saunum, the Estonian electro heater that boasts a “revolutionary Air Blending System, which equalizes room temperature for a more enjoyable sauna session.” But I call gentle gentle but firm bullshit on this “innovation.”
With a kick ass sauna stove, and a well built, insulated sauna with a conscious ventilation plan, we celebrate the simplicity of sauna. All without mechanical fans or trying to adhere to drawings with arrows, rules of bench heights, all these well intended principles can be graciously overshadowed by the wonderful principle heat rising, and creating temperature gradient level: stratification.
I say it’s a good thing!
