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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.
lakefrontroad
lakefrontroad OP
302 posts
 
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.
tireguy
1,964 posts
 
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.
lakefrontroad OP
302 posts
 
Yes, I am.

The room hvac is designed to run a/c year round. and it needs to. Last week when the heat was on in other parts of the house and the system was off, the room was 80 degees. The heating system is below the room. Although there is insulation and three layers of buildup in the boiler room, it still heats the listening room.
sogood51
2,157 posts
 
I studed a wall across the rear of my room, insulated and dry-wall with a door. Installed my heating system at one end of this long area. I did not take this wall all the way to the ceiling...I left it 19" short.

I then built a giant muffler 19" high X 41" deep X 127" long. I installed 4 return openings into the muffler to reduce any intake noise...results: dead quiet return and you never hear the furnace kick on or off. AC unit is of course out-side. Five ceiling registers of good size are also quiet.

Of course this would not work as well in small rooms because floor space is limited...my room is still 23 ft. deep after giving up 4 ft. so this is just an idea that works for a large dedicated room with it's own heating/cooling system.

Dave
unclejeff
1,313 posts
 
Another suggestion is to put your system into a cabinet with an independant cooling/air flow system. Your room will always need air conditioning so I am not suggesting you do without, but if you were to build a cabinet for your system that has a vent coming if from below and then a vent at the top you can use a remote(attic) fan to move the air. This will avoid adding excess heat to the room during the summer and you can not use it during the winter when you want the extra heat.

All of the above suggestions using baffles,etc. can work but today's 'high efficiency' systems might not be able to force enough cooling air around all of your modifications to keep the air flowing at comfortable levels. One solution to this is to get a central blower that is well over-rated for the square footage of your house. Be very careful when restricting air flow: you might wind up outsmarting yourself and creating the a very quiet room....from hell.
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