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Basement AC ducting questions...
In the process of finishing my basement after 17 yrs. of ownership and have already roughed in the heat (hot water baseboard) but have questions/concerns about the basement AC.
House was at one time heated & cooled with one forced air unit in the basement. I have since installed a high efficiency hot water boiler w/ baseboard and had two air handlers installed for the AC, one in the basement and one in the attic for the second floor - pretty big undertaking to change the duct work and do it correctly. By correctly I mean that...I'm pretty anal and did not want to see miles & miles of flex, nor did I want duct installed on a skew - square, level & plumb only. Finding the right contractor took some time to say the least.
The contractor changed the duct work in the house from single zone to two knowing eventually I planned to finish the basement and I believe, sized the 1st floor AC equipment accordingly and left some duct (both supply & return air) in the basement rooms.
I know this isn't the best due to stealing from the 1st floor and no controls (t-stats) but due to the design of the finish I believe very little AC will be needed. All exterior walls on the interior side have 2" Styrofoam glued to them and perimeter interior walls will have R-13 or 19 fiberglass in them. There will be 3" fire & sound batts in all the 1st floor joists (basement ceilings). As for humidity it seems to be a very dry basement with no water problems what so ever.
My questions/concerns are...
1. Does individual room supply air duct & return air duct sizes have to match? I may not be able to match the return air ducts, some may be slightly undersized.
2. Most rooms to get sheetrock ceilings. Regardless, is it customary or standard to install small pc. of flex prior to installing the ceiling to register boxes?
3. Do I need to install fitting with adjustable flaps to control air flow, I believe they may be called balancers, on each supply? If so, I'm confused how I'd know where they need to be set prior to sheetrock install.