Arrived on site to diagnose air flow issue on a 3 zoned heat pump system. Inspected all zones and thermostat. Inspected attic and indoor air handler. Inspected system operation. Inspect out door unit. Che led refrigerant pressure and inspect ducting layout and duct sizes. The summary of findings are as followed. Air handler 1. Found no very low air flow to master room zone 1. 2. Found duct to master bed room to be undersized and not providing enough air flow to bedroom. Should have another return vent in home. 3. 4 ton unit with only 1 return on first floor and is under sized creating high static pressure within system. 4.Found air handler ducting to be using old gray flex ducting and is in bad condition as part of the ducting insulation is falling part losing cold temperature in attic. 5. Ducting lay isn’t the best design for home and system for proper airflow. 6. Found 10 inch damper for zone 3 will not open or close allowing all cold air to go to zone 3 since it is always open