I got called to look at a system where 4 of the ceiling diffusers don't have much air movement. These 4 runs are the first off the trunkline. Some back story when the system was installed 5 yrs ago (heat only) everything worked fine ,good airflow and even heating. Now 3 yrs later they have ac installed and now they have the problems. I checked the blower speed and its set for hi on cool the blower is clean and the system is charged. I'm kind of at a loss as to what to look at next. Im wondering if there isnt a problem with the coil finns bu what doesnt make sence is the rest of the building ti got goo airflow and heating an cooling properly. Any advice is greatly appreciated