Cabinet clearance for Audio Acoustics LS16 tube pre-amp?


I am in the process of designing a built in cabinet for my stereo system. The owner's manual for the Proceed HPA2 amp is very clear about clearances for air flow. And even in the summer it almost never feels very hot as it has enormous aluminum heat sinks with completely open airflow from top to bottom.

The owner's manual for the LS-16 does not give any specifics. It says things like "adequate airflow" and that with a closed back cabinet, which mine will be, an exhaust fan is "desirable". That's about all they say. And it runs noticeably hotter than the amp. The top is never too hot to touch by any means but it is warm to the touch. Currently it sits on top of basic component stand and is up on some raised blocks so it gets all the airflow it could possibly need.

I could put it on top of the built-in shelves but I'd prefer not to. I'd also prefer not to have an exhaust fan humming along all the time. But, I don't want to shorten tube life or hurt the unit either.

Any recommendations? Precautions? Prior experience with your set-ups with tube pre-amps? 

Thanks,

George
n80
It came as an email notice.

The other problem I have with putting the pre-amp on top is that the top shelf will have to have substantial openings for all the cables to go down through and the Transparent RCA  and balanced cables have 'bricks' on them requiring even more room for cables. Such openings would be fairly ugly and as mentioned this unit is supposed to be 'part of the decor'. I like things nice looking but this is my wife's room too.

If the pre goes on top it will be sitting next to the TT.  Was hoping to have the TT as the only thing on the top. That way it would only require a small desk type grommet for the RCA and power cables.

Designing this unit is really difficult. If all I needed to do was make something to hold audio equipment in the most effective way this would not be that hard.

That it is part of a built-in system that has to fit the room and the built-in bookshelves that will go beside it adds another level.

That it has to look good and fit with the molding and trim of the room adds yet another.

At this point my plan (which changes every 10 minutes) is to have the pre-amp on the next to highest shelf. It will have nothing within 10 inches either side of it. It will have 3 inches clearance above it and it will be on blocks giving it 2 inches of clearance below it. It will have six inches clearance behind it. The shelf below it will have vent holes. There will be no heat producing components anywhere below it.
I checked out the link to the fans cleeds provided. Interesting. They do make a front exhaust model which would be the only one that would work for me but it would suite the purpose.

Sound level is reported as 24 dB.

While I’m not a major audio tweaker I do wonder what folks with power conditioners and Noise Harvesters in all their outlets would say about putting an electric motor physically on top of their pre-amp? Maybe no issues at all. I just don’t have any idea.

As mentioned I could put a fan in the false wall on the back. Initially I did not think it would have enough air flow but if it blew outward (into the room) over the top of the pre that might work since I could provide entrance for upward airflow drawing cool air from the bottom of the shelf unit.
One way to get an idea of how hot it gets is make a box out of scrap wood about the size of the opening you want the preamp to fit in, set it over the preamp and run it for a few hours and see how hot it gets. That's the way I was thinking about the fan. Use a  small flush mount in the back blowing the air  outwards , get one with a thermostat I doubt it would run that often. 
n80
I checked out the link to the fans cleeds provided. Interesting. They do make a front exhaust model which would be the only one that would work for me ...
Same here, except I use the rear-exhaust version.
Sound level is reported as 24 dB.
My listening chair is about 14 feet from the AC Infinity unit and I never hear it.
While I’m not a major audio tweaker I do wonder what folks with power conditioners and Noise Harvesters in all their outlets would say about putting an electric motor physically on top of their pre-amp? Maybe no issues at all.
I have no issues with noise from the AC Infinity unit. I do plug it into a separate outlet, along with things like the Littllite that I use over the turntable. All my other equipment goes into a power conditioner.

I’m not sure why you consider the information I’ve offered here “petulant” but I’m providing it anyway for the possible benefit to others.

@cleeds Thank you for the info. I do appreciate it.

"I’m not sure why you consider the information I’ve offered here “petulant” "
Maybe this just rubbed me the wrong way:

"It’s just that you don’t like the advice offered."

I did not think that it was the correct assessment or a necessary one. Again, maybe its just me.