Does Pass Aleph 3 heat up the room like tube amp?

my experience has been that if you choose a system based on the heat that it makes (or doesn't), the sound will reflect that.

If the heat issue is really that bad, look into class D amps.

There are probably other alternatives though. You could vent the heat out of the room via the ceiling or a vent near the ceiling. Or you could use more efficient speakers and run a smaller amp.

My DNA-500 used to run pretty cool and I kept it on all the time. It would be worth auditioning.

Some of the amps on offer from the companies you mention offer a switch that lowers the bias and allows the amp to run a bit cooler when not in use or not being used for critical listening. Didn't know if you were aware of that or if it would make a difference, but just thought I'd mention it since I didn't see it mentioned above.

Kentchai, Plinius now makes class A/B amps that they claim sound "frighteningly close" (see their website) to their Class A amps.

I own a Plinius SA 201 and it sounds great to me. I have not been able to compare it to their Class A amps. To my ear its sound falls on the warm, musical side of the spectrum, which is what I think you are looking for with a class A amp. It runs warm but not hot.

I changed from an Aleph 3 to a 22watt SET, now that is hot. The Aleph 3 you can put your hand on for 10-15 seconds, the SET less. The SET in practice produces far more heat, it is useable, with some discomfort, in the Summer. I never kept either on all the time. The SET of course you would'nt and I agree with Truman, the Aleph 3,warms up to a good performance, quickly.

I absolutely do'nt want to reopen arguments about world resources, but personally, I find it difficult to waste electricity, sourced from fossil fuels, leaving a class A amp on all the time. Other people think differently I know, that's up to them