Hi 127, Lo 73 (new install?), avg. 100. I did what gutter suggested and raised it off the unit underneath it by about 1/4". (That lower unit also produces some heat but not a lot.) 622 stands in free air, but gets direct sun in a warm room. I'll deal with that soon. I'm also going to get a fan on it, perhaps a laptop cooler. The unit is warm to the touch all over and a bit warmer in the left rear corner - I assume the HDD is there...