Q: iMac 27" Space Requirement

The exhaust vents are at the top, they can get very hot. I'd be sure to leave plenty of space so as not to restrict airflow.

I agree with Mike, all iMacs since the 2005 style began have the exhaust out the top...keep some clearance there so the airflow is not impeded.  If you have a shelf above the iMac, see if you can pull the iMac forware enough to have the vent out from under the shelf...you can see the vent, it is a slot across the top that is obvious.

I'm starting to question myself. From the pictures the 2012 iMac appears to have NOT vents on top? My experience is with the previous model 27".

Mine is also the last before the new ultra-thin model came out...there has to be a vent, though, as I believe they still have fans.  Some how the heat has to dissipate.  I still sy keep it from being too tightly enclosed, these things make heat.

There are clearly shown bottom vents, the question Mike and I kept coming back to is the top...I thought they still had top venting, but may be air is forced in, around and back out the bottom.  Take a look when yours arrives and make sure the vents are all kept clear.

And please let's know if there are indeed not top vents.  Enjoy that new iMac!

Don't know about you Mike, but I am heading over to the Apple store this week to take a look for myself.  Store is only about seven miles away.

Lemme know if you will. I have to avoid the Apple Store right now......have taxes and a vacation to pay for.

Ha, where is your dedication don't let a trivial thing like money keep you from the Apple Store :-)

Great pic...so it looks like the venting is all from the bottom.  Must be using air intake and exhaust through all of those openings along the bottom edge.  That makes the task of keeping the vents clear a lot easier since you don't have to worry so much about top edge clearance.

Thanks Iwaddo. I'll be interested to see what kind of temps these new iMacs run. Being that heat rises at least with the previous model that heat could escape out the top, now it as to be drawn in, circulated and forced back down and out.