Originally Posted by CharlieO
But the sounds of it, the real issue is not with with the HVAC unit if you can raise the temperature that quickly with just register Blowers, the system seems to be working it's just either the air is not getting to those rooms be sound like those rooms of the furthest from the units, seems like they're upstairs rooms when you talk about tearing theceiling down. You may have leaks in the ductwork, you may have issues with insulation in the rooms and the attic, around Windows, storm windows.
Without supplying a whole lot more information it's hard to say exactly what they would be.
As far as quieter register boosters, don't know what kind you bought, Do some research of different manufacturers and see if they give you a noise rating.
YOu are right that these rooms are the furthest from the furnace.
We started off not looking at the HVAC. We have a cantilever so we opened it up and reinsulated it really well. No difference to the room temperature. We had decent attic insulation, but added more and made sure the soffits weren't covered. No difference in the room temperature. When we blocked off a couple of registers it did bring the temperature up a little bit, but still not to a comfortable level. We checked for air leaks around the windows and they are okay as well. We have return air ducts leaving both rooms, so the air isn't getting stuck in the room.
I wasn't really able to find any information indicating any external register boosters are quiet - just inline ones that would require opening the ceiling below and putting in access panels so the fans could be cleaned.
We have been told that the furnace is a bit big for our home size which would have the furnace turn on and off quickly - maybe this would prevent the warm air from reaching the furthest points to provide enough warm air before it shuts off?