John Sayers' Recording Studio Design Forum Archive

I see several topics about this subject. I'm hoping my question will be direct enough to warrant its own thread. I've got two or three bids for HVAC units. Two are for mini ductless splits. The other is for a single split central heat/air. I'm concerned about power/amp draw. But my question is this: If in soundproofing we're concerned about the weakest link; the aquarium example, wouldn't ANY duct defeat this idea? Air has to escape and enter through the air ducts and ventilation system. What is the difference between that and having AC and heater wall units? The air/sound is going to enter escape either way, no?

That's what duct silencers are for--- to act as a muffler. This maintains the isolation of your rooms.

Greg

Great. Is this something most contractors or HVAC installers know about?

Great. Is this something most contractors or HVAC installers know about?

They should understand that basic concept, but they might not understand the critical importance for recording studios. There are commercially available "silencers" and "mufflers" for HVAC systems, but they don't go far enough to be useful for studios. Most home recording studio owners end up building their own silencer boxes, or hiring someone to do it for them. If your HVAC contractor has previous experience specifically with recording studios, then he should be aware of the differences, but those contractors are few and far between... You might have to "educate" your contractor a bit, to help him understand the importance of high isolation devices for studios. He also needs to learn a few other things that he'll have to do differently for your studio, such as making sure that the speed of the ari coming through the registers is much lower than for a typical house, school, office, store, church, etc. The air flow velocity at the register must be less than 300 FPM. Any higher than that, it the air flow itself is too noisy for a studio. So your contractor will need to use larger ducts and registers than he would typically use, in order to have a higher VOLUME of air that is moving at a lower SPEED. Etc.

HVAC is a big part of studio design. Hopefully you can find a local contractor who understands this, and does have experience with studios!


- Stuart -

Thank you. And while I'm at it do you, or does anyone have an opinion between a mini ductless split and a central air split? It seems like the central has more ducts? Ductless SOUNDS really good but it still requires a duct system, no?

...do you, or does anyone have an opinion between a mini ductless split and a central air split?

For just a single room where extreme quiet isn't necessary (eg, control room, amp iso booth), a ductless unit is a decent option. But if you have two or more rooms, then it makes sense to go with a ducted AHU that is dimensioned to handle all of the rooms with one single system.

It seems like the central has more ducts? Ductless SOUNDS really good but it still requires a duct system, no?

Right! For a studio, you still need ducts to bring in the fresh air and exhaust the stale air. You don't need that for a normal house, office, shop, etc. since those are very "leaky": plenty of air movement. But for a studio, which has to be sealed very tightly, you do need it. And since you need a duct system anyway, it makes sense to put the actual air conditioner as part of that duct system, outside of the room, so you won't hear it at all. So the duct system recirculates most of the air through the room and air conditioner AHU, as well adding some fresh air to it, and removing some stale air from it.

- Stuart -