Technician was informed of temperature difference from the front of the house to the back. Technician inspected duct work found d a metal box with 3 exits. 1 feeding the main house then left feeds the front room right feeds the back room no dampers are in the branch’s so we can not adjust air flow. Technician recommended replacing ductwork due to age and to be able to adjust airflow to allow better temperature in the other rooms. Customer is thinking of zone board with 3 dampers and 3 thermostat field supervisor to give best solution.