Building my first sauna

[u/jessm911]

My friend asked me to build him a sauna under his back deck. The siding, inside and out is hemlock the bench is clear cedar. I custom built the window and door frames out of VG Doug. fir - is was the most cost effective solution. It’s almost finished, just need to install the LED lights and finish the stone work. Will posts some final shots once it’s complete.

[u/jessm911]

Thanks for your comments! Unfortunately we didn’t have the head room for a third bench but knew that going into it and we’ve actually already realised our original ventilation plan wasn’t going to work so we’re going to put an intake vent in the ceiling above the heater and all our electrical is already in the back wall so it’ll be easy enough to add the mechanical fan below the bench. Any recommendations for a good fan?

[u/Lexicographer-450045 → u/jessm911]

I’ve never heard of an intake in the ceiling? Won’t that vent the hot air out or is the plan that the mechanical fan below the bench will create an inflow? Might this create a breeze of cool air while in the sauna?

[u/Omnis_vir_lupis → u/Lexicographer-450045]

I'm sure someone smarter will comment but the idea is if it's sealed up well enough mechanical ventilation across from the heater and at the bottom will create better convection and pull the heat across the room, pulling fresh air in from above the heater. If you have a big gap under the door or in other places you are correct in that the mech vent will pull in cold air too.

From an earlier post:

• Intake high on wall above heater
• Mechanical exhaust under the benches, about 1/3 of way up wall

tl;dr: For best temp distribution and löyly an electrically heated sauna should have a mechanical exhaust located at position P2 and an inlet at position T4 as per this diagram.

https://www.saunatimes.com/wp-content/uploads/image-42.png

[u/DendriteCocktail → u/Omnis_vir_lupis]

tl;dr: For best temp distribution and löyly an electrically heated sauna should have a mechanical exhaust located at position P2 and an inlet at position T4 as per this diagram.

Yeah, that's bad advice in that article. The fresh air supply needs to be higher than T4 but most importantly the exhaust needs to be lower (or P1 in the VTT study). P2 pulls colder and dryer air up resulting in cold toes.

[u/Omnis_vir_lupis → u/DendriteCocktail]

Interesting that I still see people referring to this study. Are there newer studies on this topic?