Basement Studio

[gullfo]

do a search, i think Stuart had posted a length article on this forum a few years back. also Rod Gervais has a spreadsheet for calculating the hvac requirements including latent heat, moisture etc factors.

[marc777]

Is it a must that you have 2 silencer boxes per run. ex. 8" into silencer-> out of silencer> back to 8" duct> into silencer> into room. Can I get away with 1 rigidly built silencer? Does the length of the duct determine if I should use 2 silencers. (at unit and into room)
I believe I am overthinking the whole process. If I have a room of 200sqft, 1 9in round duct should be sufficient for the room (7air changes), so in reality I need to make the silencer box speed up air (make smaller at the inlet) and slow down the air into the room. So should my outlet of the silencer into the room be a touch bigger than the 9" area of the duct coming into the silencer to slow it down enough? and I will bring fresh air.
I am going to start running electrical this week and hopefully get the HVAC ordered. HVAC has me held up. Thats why I need to figure out the air flow and silencers quickly.
I really appreciate the feedback I have been given.
Marc

[gullfo]

so keep the 8" duct and into the silencer entry. then after the twists, into an expansion plenum to slow it down. you're only using the silencer to prevent a direct path via the opening (which will be bandwidth constrained due to its size) and avoid machine or inter-room air space noises from traversing the mass boundaries. in most cases a simple U would suffice. this reduces size, and friction.
and of course setting the HVAC equipment correctly to avoid noise (decoupled machinery), speed, cross-duct to allow balance between supply and return, low noise vent registers, etc etc etc.