[masraum]

Originally Posted by 908/930

How much longer do you expect the run to be? Does the heating cooling adequate in those areas now? If not, now is the time to tweak it. I do not use flex lines but would think you can just hose clamp them on to the fittings. Once inside the building envelope slight leak is not a big deal, different when in uninsulated area. With pipe to fittings just use a couple of duct screws to secure, you can also use sealant if you really want it air tight.

I suspect the run will be if not the same, then within 2-3'. Upstairs gets warmer during the day, but I think that's more about inadequate insulation (thread coming soon) and possibly HVAC design (need additional return?) than HVAC capacity. Miraculously enough, the entire HVAC system was installed in 1991, and other than a slow leak, still cools REALLY well. We are looking into replacing the system, probably within 9-18 months. The attic has 2 whirlybirds, but no soffit vents, so that's another issue that I plan to rectify.