An HVAC system includes an evaporator coil disposed between a supply air duct and a return air duct. A re-circulation duct fluidly couples the supply air duct and the return air duct. A damper is disposed in the re-circulation duct and is moveable between an open position and a closed position. A controller is operatively coupled to a variable-speed compressor, a variable-speed circulation fan, and the damper. Responsive to a determination that the variable-speed circulation fan is operating at the minimum speed and the suction pressure is above the pre-determined threshold, the controller signals the damper to move to the open position. Responsive to a determination that the variable-speed circulation fan is not operating at the minimum speed or the suction pressure is below the pre-determined threshold, the controller signals the damper to move to the closed position.