A blower unit for a vehicle heating, venting, and air conditioning (HVAC) unit is disclosed. The blower unit includes a case member that defines at least one exterior air intake aperture and at least one interior air intake aperture. The blower unit also includes a sealing member, a first door, and a second door. The first and second doors can move independent of each other. The first and second doors can be positioned in a mixture position to allow air flow into the blower unit through both the exterior and interior air intake apertures. The first door, in the mixture position, is sealed against the sealing member. As such, the first door and the sealing member cooperate to reduce air flow out of the blower unit through the interior air intake aperture.