Technician arrived on site. Call was for low airflow upstairs. Unit had been replaced about 3 years ago. Along with the ducts. Downstairs is cooling great. Upstairs is getting almost no airflow. Found a 12 in duct supplying the entire upstairs. As a result there is no airflow. Talked about relocating the unit to the attic. Need to get field supervisor out here to do a job walk and provide estimates.