Am I reading this right? Is there no heat exchanger in the ventilation? That seems like an obvious improvement.
A 45 year engineer clears up electric sauna ventilation
11–20 of 74 posts
Re: A 45 year engineer clears up electric sauna ventilation
#12Am I reading this right? Is there no heat exchanger in the ventilation? That seems like an obvious improvement.
The ventilation within the sauna is actually more effective the greater the temperature gradient between the entering low-CO2, cold air and the stale, hot air in the sauna. You want the entering air "falling" on the stove because it's colder i.e. denser than the surrounding air. It then heats up and mixes with the hot air in the sauna.
That being said, almost any real implementation in a cold climate place like Finland would have a heat exchanger at the building level for a mechanized ventilation system. It's of course still not 100% efficient so the circulation system within the sauna still works.
Re: A 45 year engineer clears up electric sauna ventilation
#13tldr: place air inlet above the heat (B); air outlet on the other side at the floor (D). See figure:
https://www.saunatimes.com/wp-content/uploads/IMG_6556-1-560...
This ensures: 1) quick heat up of fresh air 2) vertically uniform heat 3) creation of better steam
Re: A 45 year engineer clears up electric sauna ventilation
#14[flagged]
When writing technical articles it is probably best to write as simply as possible, especially as you might have to have many technical terms in the article which will limit understanding for non experts, also English is not this guy's first language I'm guessing?
Re: A 45 year engineer clears up electric sauna ventilation
#15Am I reading this right? Is there no heat exchanger in the ventilation? That seems like an obvious improvement.
The ventilation within the sauna is actually more effective the greater the temperature gradient between the entering low-CO2, cold air and the stale, hot air in the sauna. You want the entering air "falling" on the stove because it's colder i.e. denser than the surrounding air. It then heats up and mixes with the hot air in the sauna. That being said, almost any real implementation in a cold climate place like Finla…
Also to remember is that amount of moisture added in usual sauna session is not insignificant. Throwing at least couple of litres of water on stove is entirely normal in addition to whatever is perspired.
Handling this level of possible condensation might need additional considerations.
Re: A 45 year engineer clears up electric sauna ventilation
#16[flagged]
Paraphrasing, if you can't explain it to a fourth grader, you don't understand what you're talking about yourself.
Re: A 45 year engineer clears up electric sauna ventilation
#17Am I reading this right? Is there no heat exchanger in the ventilation? That seems like an obvious improvement.
I'm not really sure what you're critizisng? This was a study done in the early 1990s looking at what would be the best way to build a sauna. This isn't a study in HVAC optimization for a house.
FWIW current finnish building code more-or-less require a heat exchanger in the exhaust air flow. It didn't in 1990.
Re: A 45 year engineer clears up electric sauna ventilation
#18tldr: place air inlet above the heat (B); air outlet on the other side at the floor (D). See figure: https://www.saunatimes.com/wp-content/uploads/IMG_6556-1-560... This ensures: 1) quick heat up of fresh air 2) vertically uniform heat 3) creation of better steam
I wonder if this holds true for a wood burning sauna too? An active fire in the stove creates a massive draft that'll pull air through the stove and out the chimney.
Re: A 45 year engineer clears up electric sauna ventilation
#19Some additional discussion on Reddit https://www.reddit.com/r/Sauna/comments/1b2skn6/a_45_year_en...
Re: A 45 year engineer clears up electric sauna ventilation
#20The sauna design rabbit hole is a very deep one.
If anyone is interested in more information about sauna design in general, Trumpkin's Notes are by far the most referred to guide out there. [1]
There are also new products [2] which help improve saunas which are not ideally designed or where there are constraints (ceiling height mostly) to deal with.
1: https://localmile.org/trumpkins-notes-on-building-a-sauna/ 2: https://saunum.com/en/