Some Rheem furnaces can be converted in the field from upflow (as-shipped) to downflow, horizontal left or horizontal right as necessary.  In addition, there are different venting options, including a zero-clearance option, to give the installer flexibility in locating the venting for the furnace.  

Conversion kit (RXGY-CK) required for certain applications.  An additional zero-clearance conversion kit (RXGY-ZK) may be needed for other configurations.  Please see chart below for details.

Click here for Rheem Furnace Non-Zero Clearance Vent Conversion Kit (RXGY-CK)