The sensor is located on the case (not near the exhaust) of the server. With the structure of my appartment this is the only place I can realistically put my Server but sadly also the hottest place in my appartment.
The outside temperature is supposed to reach 36°C today so I expect the ambient temp for the server to rise another 2-3 degrees.
For the rack in the closet, I cut a 4" duct off the ac, and piped it into the top of the closet. For one of my computers, it seemed to always run hot, so I bought two 6" box fans and mounted one over each of the two CPU. I have a little gadget that comes with Open Hardware Monitor so I can keep an eye on it. Currently running 100 freedom degrees, but it will fluctuate +/- 10 degrees depending on load. The only downside is they are a bit noisy, not extremely, but you can hear them buzzing away keeping shit cool so I don’t complain much and just turn the music up. LOL