Abstract: A system and method for improving the efficiency of air handling units by reducing the static air pressure within units. The system and method utilizes rotary union mounts to fluidly connect the heating and cooling coils within the system. The rotary union mounts allow the heating and/or cooling coils to be rotated flush within the housing of the air handling unit when the coil(s) are not in use and thereby out of the air flow path. Rotating the coils out of the air flow path reduces the static air pressure within the air handling unit and significantly improves the efficiency of the system by reducing the horsepower requirement and power consumption of the system fan. The rotary union mounts allow the coil(s) to be selectably rotated out of the air flow path based on system demand requirements.