Everything done in this house was wrong. It is a long, high, old, one story with no wall insulation. It has a 1-1/2 story addition; walk down to FR, walk up to large Master and big bathroom.
It is 2500 sq. ft. & has a boiler, so there is an air handler system in the attic and a Trane 1000 (11 years old) outside.
Before I started closing some vents, and even with some closed, the air flow into the FR is pathetic. Yet, this area is closest to the air handler. For 5 years, I have been closing 3 of the 14 vents off, with slight improvement, but it is ridiculous to have it cooler in the old part of the house then in the FR.
I'm spending up to $175 on AC bills a month. Recently, I decided to close two more vents, which improved the FR some. However, after reading this site and others, I am afraid if this will cause the compressor to burn out or the coil to freeze.
There is even a flapper near the air handler, which I have for 10 years turned at a 45 degree angle to try to send less air to the old part of the house, which is furthest from the air handler. For whatever reason, things are the way I describe above. Why the air wants to go to the old part? I wonder if that is because the largest air return is located there? There are only two other normal vent size air returns in the newer part, which sounds like bad engineering.
So, from 14 open vents & 3 closed ones, I went to 5 closed ones. Is that too much and will cause major strain and problems? I don't even know where the coil is on the outside Trane unit. There is an external pipe running up the side of the house to the air handler, and one section is covered with a black foam sleeve, and I think there is a coat-hanger size copper wire from the Trane unit to around the external pipe mentioned.
I don't understand how the vent closure can damage the system when the air flow out of some vents is less than half that of others. I could see if I had every open vent blowing like mad, but they all are not. Closing the 5 off increases the flow to the weak ones, but those weak vents still are not blowing that hard at all, though the help is enough to satisfy us, as I don't know if I've gone too far already or not. I'd appreciate any help.