Who has solved the HVAC air noise problem?

I am in the redesign stage of a totally dedicated listening room which will inlcude tube amp, pre-amp and cd player. The reconstruction will include a flat ceiling and tons of sound isolation and insulation. The central air system for the house with constant air flow produces way too much background noise and hum through the vents. I want to add a separate dedicated a/c system for just this room (25Lx15W x 9.5H). I am looking for the advice of those who have managed to baffle internally in the ducts sufficiently to eliminate the air flow noise and machine hum, while still having an effective a/c system. I want an invisable a/c system with five overhead vents. Duct size should not be a problem as the walls will be at least 12" thick at one end. I presume that fiberglass or lined/insulated sheet metal with all surfaces covered are the way to go. BUT, I really don't know. What I know is that I want to be able to never hear the environment, only the music.

All thoughts welcome including my obvious need for more therapy.

Bill E.

Gardengirl must have taken lessons from my wife. I don't understand a thing she says either.

Bill E.
The proposed fix by the acoustical consultant is re-routing the duct to make several turns and line the duct with acoustical liner. The contractor prefers to install baffle boxes since shop time would be higher and field time would be almost none.

Results to follow.
I would advise full use of the on/off switch for the AC. You are spending mucho dinero and still may not fix the problem. Spend the money on concert tickets or a great new pair of headphones for the times when it is just too hot or cold, or turn it off just prior to listenting sessions. You paid good money on your gear to hear "gnat belches at 50 ft". I understand. Unfortunately a 35-40db HVAC system is not tolerable.

As a recording engineer just when you think the venue is quiet you put your headphones on and hear some motor or HVAC system noise close by. It never fails. I remember JA from Stereophile recalling just an instance recording Cantus.
I will never compromise or surrender. It's much more fun to have intricate interiors to metal boxes. We feel that the baffle boxes will solve the problem and eliminate the hum. It's really quiet, but annoying.

If I could deal with the heat and no air it would be different. The room is tight, and shortly will be sealed.
Therefore, it's necessary to have the a/c on to bring in intake air.
Bill- weren't you planning on running ac in the winter in this room? As a form of heat to offset the BTU's of heat from your amps, or had the plan changed? In any case I am quite curious how this will turn out.