Originally Posted by uxbridge
What is the square footage of the home and its age?
2000 Sqft above grade (1k per floor) a bit less below grade about 900, about 650 Sq finished space. The house is 2 and a half years old.
What size is the furnace BTUH, Eff.(hi or mid), Blower capacity(1200-1600cfm)? What size is the A/C?
Not sure. I'll confirm tonight. They call it an "energy star" house - which I assume is primarily driven by the fact that the house and windows are pretty efficient. But the furnace selection may have been a factor. It is forced hot air, gas powered, with air conditioning.
What type of Bypass duct are you using?
Is this for the zone dampners? The Dampners are motorized, not springs. My HVAC guy was recomending allowing them to go to 80% closed in the "closed" position rather than closing them 100%, using a bypass dampner and feeding the treated air back into the return. He felt it was more efficient, as you aren't cycling the air, and you let a small amount go into the non-called zones. Seemed logical to me. Is that what you were asking?
Could you use the soffit as the return duct and just line it with acousti-duct insulation?
Don't see why I couldn't. Bryan Pape is helping with accoustics, so I'll need to see if he was planning to use that real estate for treatment. I'll need to run electrical and low-voltage, but that shouldn't be a problem unless code says otherwise.
Can you bring the return flex duct through the ceiling beside where the beams meet in the utility room and then tag it in to the return main, doing the S turns (if required incase it still is transfering noise)in the utility room ceiling.
There is a lot going on right at that intersection, so there might be a traffic situation. Assuming I am going to run flex, am I correct to assume I could go over the beam closer to the water heater, and then come back with flex (with the desired S turns)?
I'd strongly suggest that you upsize the 7" flex to 8" flex for lower branch duct velocity. Look at the link provided by Bigmouth, at 200cfm a 7" has a 600fpm velocity and an 8" has a 500fpm velocity. In residential constant flow design, 600fpm is recommended in the branch ducts, however you are building a quiet theater and your installing a zoning system that will run at higher static pressures. The cost difference will be minimal maybe $15.00 per 25' lenght.
I will request this change. Thanks Bill, this is really helpful.