I came out for an airflow issue the north east bedroom is only getting a trickle of air and the attic is staying cool. I checked the entire duct system over. I found a couple issues. The return ducts are undersized for the system. Currently has 3-12â€ returns, which is only 900cfm and the system needs 1600cfm. The supply plenum has a 10â€ duct coming off the end of the plenum which is taking most of the air and not allowing the supply plenum to pressurize and disperse the air properly. I recommend increasing the 2 main returns to 16â€ ducts and moving the duct off the endcap and back on to the top of the plenum.