Hopefully with a "catchy" title, some of the experts will give their opinion.

I'm wanting to move Rachael from a happy, unconfined space, to a potentially unhappy confined space.  I need to know if this will be a problem though before I do it.

It would be placed in an entertainment unit, open in the front and partially open in the back, on a shelf which would allow about 7" of open airspace above.  There is a small, 1.5" top panel which does block a bit off.  There is ample side-to-side space of about 9", so it would end up being in about 2.6 cubic feet of airspace around it.

I'm just not sure how hot it would get in a somewhat confined area as this, and of course don't want to experiment and find out.

Also, does it get hot underneath too?  I've never really checked because it didn't matter, but enclosed it might.

One other alternative is a high quality longer power cord, but to me the Pangea cord I could switch to seems to be incredibly heavy and would really place a strain on the connection to the unit.

Thanks for any help.

I read somewhere that if you use a fan, make sure it is pulling hot air off the unit, NOT blowing air on it. Is this the conventional wisdom?

Yes, but what I recall reading is that in a confined space one is better off pulling hot air out, rather than just recirculating it. Since it sounds like this isn't all that confined it may not be a big deal. And again, it's just something I read, may not be true. It was on the internet though!

Can you post a picture of your cabinet showing the side and back that you described?

The air itself doesn't know which way it's going, but from a transfer perspective it's more efficient to have a passive intake and an active exhaust, than it is to have an active push on the intake. This isn't always the case: in a perfectly sealed system with one intake and one exhaust and no obstructions (say, a pipe) it doesn't matter where the fan goes, but as soon as you start putting things in the way you start want an active draw. Mostly this is because you can be more assured that you're pulling the majority of your waste heat out, as opposed to hoping that overpressure shoves the excess out of the way.  

Anyway, when dealing with messy systems (from a fluid standpoint) you generally want your fan on the exhaust since that will guarantee that the waste heat will be drawn away, especially since you don't particularly care where the replacement air comes from as long as it's cooler than your exhaust. The opposite is true with fully open systems, in those cases draw fans don't work at all since you don't have any guarantees that the fan will pull from the place you want, though you're pretty sure where the air will end up. FWIW, this is the reason why desk fans work better when pointed at you (fully open system, directed column of air), and single box fans in windows cool down your house better if you turn them around and have them draw from your house and out your window (mostly closed system, exhaust guarantees waste heat rejection).

Yes, I'll agree!!

Thanks Colin B.

I managed to get a picture to show the situation.  I know it is an outrage, but yes, I keep a large box on top of the amp to keep dust out.

If I do move it to the center cabinet, I'd have it sitting on the center speaker (with padding between of course), and I'm not sure that would be acceptable being so close to a speaker with vibrations?

I'm always worried Steve will banish me upon learning what I've done!!  But she's too expensive to get dusty!!

I am now rethinking the idea, as vibration was a secondary consideration but maybe that ends up being the major obstacle.  I was just thinking that the center speaker wouldn't be a problem, as only the two floor-standing speakers would be used with Rachael.  But, whenever the regular system is on, the center speaker would be on and vibrating, and probably not doing any benefit to the amp.  

I don't know if there are any general discussions here about the effects of vibration on these tube amps?  

I really would like it though if I could get the amp there in the entertainment unit.  I could possibly attach a couple of brackets to the wall, so it would be a shelf in the entertainment unit that the amp would be resting on, instead of the speaker.  At that point, it seems pretty close to the current situation being so close to the one large floor-standing speaker.

Those look like APC backup power units under the center speaker. Can you swap the APC's with the center speaker?  It looks like the Rachael then could sit in between the APC units.  Then put a shelf in for good measure and you may have enough air above to not need any fans at all.

Regarding Scott's suggestion, I actually brought the APC units into the cabinet to raise the center speaker, as it was a bit low just resting on the bottom.

I also will probably have to leave the box on Rachael, as cat hair isn't as big a problem as the actual cat, who is known to be curious about anything and everything.  He climbed a 12-foot ladder one time when I was changing some light bulbs, so yes, he can get into interesting dilemmas.

Now here's an update.  I had forgotten how heavy Rachael really is, so setting the amp directly on the speaker won't be good in my opinion.  So I'm left with either putting in a shelf to hold the amp, or doing something completely different, or just leaving things as they are.