For Internal Use Only. International Sauna Association, Sauna Dynamics Group. Please keep this document, the name of the business if you know it and all images confidential.

A sauna heated with a Harvia M3. The M3 is known for producing too much radiant, here the loading door faced the benches rather than perpendicular which makes the problem a bit worse. The heater is along the same wall as the bucket in the first set of images so the fire door is directly facing the bucket.

I believe the benches were 45cm and 90cm high. The top of a Harvia M3 is typically 71cm so top of stones maybe 75-80cm.

 

I was not able to get accurate temps due to time constraints. My guess is that actual head temp here was somewhat north of 96°c. Whatever head was, a 54°c foot is chilly in comparison. Sadly unsurprising given the low benches.

Though I didn’t get to do any rounds in this one, my guess is that it would be a bit more comfortable/enjoyable than the prior one. It has slightly less stratification, less radiant and should also have a better convective loop, all of which should increase comfort and enjoyment.

East wall (left), south wall (right):

 

Radiant from the M3.

 

And the other end of the benches. North wall (left), east wall (right):

 

Radiant – There is some heat loss through the wall (second image below) and we see 83.5°c on the wall just above the sitting bench in an area that I believe is in a radiant shadow so my guess is that ambient at the middle of the sitting bench is maybe about 80-81°c so anything above that is radiant.

 

From outside. I don’t believe this has a commons/changing area so all walls are of the hot room. There was a slight bit of sun beginning to hit the first side while the second is currently shaded. Also, note that the DC image does not line up so the measurement points appear slightly high on the image vs reality.

West wall (heater is in lower right corner). Interesting that there’s a radiant shadow on the heating pad. The sun must be heating it somewhat well.

East wall.

 

Harvia M3 Heater:

A good bit of radiant. Multiples more than an Iki Original or Narvi NC but about 1/3 as much as the Kuuma Blue Flame. Stones appear well heated.

 

And for fun

That’s all folks.