I thought I was building and advising to build saunas correctly. And for the most part, I am. However, there is one WIDE difference on what many are doing in the US compared to Finland:
Gap along the hot room door.
Finns, the pros, are nuts about fresh air and venting. With a wood fired sauna stove, this is critical yet not AS critical as with an electric stove.
Wood stoves draw air and help circulate air on their own.
But electric stoves suck, in terms of air flow and ventilation. We need to be cognizant of good venting!!
Fresh air and oxygen circulation allow us to enjoy our time in the hot room. Dizziness from time spent in a sauna is more apt to be from a lack of oxygen than too much heat. How do I know this to be true? I took 50 saunas in 12 days in Finland, and I was never dizzy.
Oxygen. Air flow.
How do we design our saunas for optimal oxygen and air flow?
- 42″ (107cm) Top bench to ceiling. When sitting on the upper bench, we want to be able to put two fists over the top of our head to the ceiling.
- 18″ (46cm) lower bench. This is optimal chair height and comfortable for most adults (no scrunching or feet dangling).
- 6″ (15cm) raised floor deck. This step up, when entering the hot room, keeps the feet warm when sitting on the lower bench as we have an air gap from the actual hot room floor to where you sit, stand, or walk.
- 4″ (10cm) gap along hot room door. This makes the Finns happy. Plenty of air flow.
- Vent: opposite wall as stove, eye height while standing. A few inches (10cm) down from the ceiling.
What’s wrong with this design?
I know, I know, while sitting on the upper bench, our feet, resting on the lower bench, are a few inches below the sauna rocks.
If we build saunas with 7’6″ (229cm), we can move everything up 6″ (15cm). This way, while sitting on the upper bench, our feet are at or above the sauna rocks. But this creates a new problem. Now we have 12″ step up from changing room floor to hot room floor. Two steps, 6″ (15cm) each can be quite clunky and cumbersome. Worse, these steps can be dangerous for children or senior adults as they navigate themselves off from the top bench, down steps and out to the lake or cold plunge water feature.
Let’s pick our poison
While sitting on the upper bench, do we want our feet a few inches below the sauna rocks, or do we want 12″ of up and down steps each time we enter and exit our sauna hot rooms? Many (including me) choose to have feet a bit below the sauna rocks and one less step coming and going, over and over.
UPDATE: SEPTEMBER 25, 2020:
I have tuned my 7′ tall sauna hot room bench heights as follows, and approve this message:
- 44” ceiling to top bench.
- 16” to low bench.
- 16” to step or raised floor.
- 5” step to duckboard, height of changing room.