In addition to the acoustic treatment
in the room, I'm also doing some design for what's needed outside the room, specifically air muffler / silencers. The problem here (as I understand it) is that ventilation must be handled by something that allows the air to flow, but kills noise as it travels through. I need two ventilation paths for my room - an exhaust for the AC unit, which generates heat that needs to be removed as it cools the inside air, and a fresh air intake, which will help keep me and anyone else from passing out from oxygen deprivation - the room is pretty near airtight, or at least it will be when I'm done sealing the door.
The particular AC unit I'm using normally requires a window to vent the hot air out. The manufacturer states that adding hoses to this exhaust can't be done, as it will cause the unit to overwork itself, so anything I do with this exhaust must allow it to flow without restriction. Since the muffler / silencer that I'll be building will cause some back pressure, I'll be adding an inline fan to help suck the exhaust through. All good, right? Well, the other concern is that we can't be pulling too much through the AC unit, so we need something to 'tune' the flow.
The design we've come up with, so far, directs the heated exhaust up through a 'maze' made of Rockwool, which will cause the sound to be absorbed as the air passes through. We also have added an air inlet, which directs incoming air (being sucked through by the fan) past the exhaust, hopefully causing a sort of vacuum, and encouraging the heated air to go towards the exhaust.
Sorry for the junior science lesson... Here's what I came up with:
A concern was raised that the air may not be 'encouraged' to rise, as there is less resistance in the air inlet path, so I proposed a few changes:
Another way to reduce flow on the intake path would be to make the side-to-side dimension smaller than the output, as shown here:
We're still discussing, and I hope to finalize and build a prototype either this weekend or over the next week.
And, any input is welcome by ya'll!