Interior dimensions were 8’ x 8’ x 8’. It had a typical American two bench setup with foot at 18” high and sitting at 37” high. There was no commons/changing space so the sauna door opened directly to outside. 

Ventilation was via gaps in the floor.

Outside temperature was 20°c, DP 12.24, RH 61%, partly cloudy.

 

Not unexpectedly, and like all Kuuma’s we’ve seen, the stones weren’t very hot. The hottest I found was 146°c while most areas were below 110°c. It takes about 120°c to make steam. Similar to other Kuuma’s this resulted in steel steam that was very hot and ‘biting’ rather than the gentle but intense steam that is generally most desirable in a sauna.

 

The heat shields work OK from the sides. We still felt a LOT of radiant on our faces and lower legs from every seating position however.

 

In these next two images we can see the radiant along the front of the foot bench with the signature horizontal falloff. FWIW, the ambient air temp @ about 5cm above the foot bench was 58°c.

This first one shows the Kuuma stove and part of the foot bench.

 

This second one shows a wider view of the foot bench. Point #1 is approximately the same in this and the prior image. The falloff from 75.6°c to 56.5°c is greater than would be expected based on inverse square law calculations which indicate about 72°c rather than 56.5. This however is due to the oblique angle. 

 

And here the temps on the face of the sitting bench. Again we see the telltale radiant signature of horizontal falloff as we get further from the stove. Normally the faces of each bench would be even and nearly identical to the ambient air temperature at each strata.

 

Ambient air head temp (official sauna temp) averaged 93°c for the time we were there. The head temp at the wall surface was 86°c which is slightly higher than would normally be expected.

Now, two critical things to notice. The face of the foot bench is 56°c which is likely what ambient air temp was at that strata given a measurement of 59°c just above the foot bench.

The wall next to the foot bench is 71.7°c. This is due to radiant heat from the Kuuma that’s hitting it perfectly perpendicular. 

 

There is a bit of area on the top surface of the Here I moved point #1 down to the top of the foot bench indicating about 62.5°c. I’m not sure

 

Measured temps. Sensors were placed on the end wall (on the left in the IR image above) and arrayed above the middle of the foot bench. Head (1m above sitting) and Mid_Back I believe are accurate. Foot is not due to radiant heat on the sensor. Actual air temp at the foot bench was about 58°c.

 

 

I think the only way to determine steam temp is to measure temp