avvidclif
Well-known member
The airflow does not cause the air to come out the ducts. Pressurizing the ducts does. The job of the AC is to pressurize the duct, either one or 2 units. The ducts relieve the pressure and you feel it as airflow. If the ducts are not properly sealed the pressure cannot build up to force air out the ducts.
My 2 cents: The AC system and ductwork was properly designed to work correctly. What the design engineer did not plan for was 3 sided ducts that are not sealed correctly in assembly, pipes running thru the ducts and not sealed, etc. All of those bleed off pressure that should be forcing air out the ducts. Someone with a temp gun needs to measure the ceiling temp with the AC running. You should be able to follow the cool air down the duct by looking at ceiling temp. If all of the ceiling is about the same, somethings leaking and you are cooling the attic.
My 2 cents: The AC system and ductwork was properly designed to work correctly. What the design engineer did not plan for was 3 sided ducts that are not sealed correctly in assembly, pipes running thru the ducts and not sealed, etc. All of those bleed off pressure that should be forcing air out the ducts. Someone with a temp gun needs to measure the ceiling temp with the AC running. You should be able to follow the cool air down the duct by looking at ceiling temp. If all of the ceiling is about the same, somethings leaking and you are cooling the attic.