When designing and building an authentic sauna, the question of inside feed or outside feed comes up a lot.
SHORT ANSWER:
I recommend feeding wood burning sauna from inside the hot room.
Reason #1:Â heat loss
There will be 25% heat loss from feeding a wood stove from the outside. This is not my figure, but confirmed by Daryl Lamppa, 3rd generation Finnish sauna stove maker. The front of the stove is thee hottest.
Reason #2: cost
If building a sauna with feed through a wall, it costs $500-$1,000 more in materials, as code requires metal framing and clearances to non combustibles.  Plus there is the intangible cost of concern to frame a stove inside a wall.
Reason #3: ambiance
A glass window helps create a warm glow vibe, gently dancing off the cedar walls. Ahhhhhh. What about the mess from feeding wood from inside the hot room?  No big deal. Get a hand broom and sweep it out once and awhile.
Hi Glenn,
I discovered your site and appreciate all the information you have here–I discovered that we have a great sauna stove mfg. right here in Minnesota–so that was good to learn.
I’m dreaming of building a wood burning sauna, so I’m looking at floor plans. I see one plan you recommend is to have the stove at the rear wall, centered in the sauna. Does this mean feeding the stove from the outside?
I was in a sauna this fall that had a changing room, and you fed the stove from that room. That seemed like a good idea to me, because the stove was inside…any particular reason for not feeding the stove from the changing room? Maybe it’s better from outside, so you have more room and less mess in the changing area?
Just curious about your thoughts on this as I start my research.
Thanks,
John
St Cloud, MN
The feed from changing room is a viable option. It saves a bit of space, and offers heat into changing room. In my experience, however, this is unnecessary. Heat gets in the changing room just fine by opening and closing the hot room door. Further, feeding through a wall requires some elaborate fire proofing and framing around the “throat”.
2 thoughts on “Wood burning sauna: feed from the outside or inside?”
Hello, I’m looking to do build our first sauna this year and we’re planning on an outside feed. I agree with your points, but in case others are looking for an outside feed as well I thought I’d share our reasons.
1. The mess stays outside.
2. There is a lounge/change room on the other side, so we can enjoy a fire in that room.
3. Probably the main reason though is that some family members react to the smell of smoke and ash. Being that this is a detox area we didn’t want to risk the possibility of someone having a reaction by introducing any harmful particles into that “clean” space. This is the same reason we decided to use alder instead of cedar.
If it were just me I’d do differently though. It sure would be nice to have a fire to look at in the sauna. Thanks for the tips, love the page!
.
Ok, you got it! Glad you have clear headed review of where you’re going with your option. Sauna on Rob!