For optimal heating performance, choose the MRCOOL Signature Series Single-Stage 96% AFUE 135k BTU. It can be installed in an upflow or horizontal configuration and is both energy efficient and quiet running. The unit's multi-speed high efficiency blower motor aids in the unit's 96% AFUE. For enhanced cooling SEER ratings, apply this unit with properly matched cooling equipment. The aluminized steel primary heat exchanger with crimped non-welded construction aids in this unit's durable build and finish. For optimal operation, the furnace features aluminized steel inshot burners and a durable silicon nitride ignitor for smooth ignition. The single stage gas valve helps to deliver heating to your home quickly and effectively. The removable floor base for bottom return air, zero step horizontal conversion and left or right utility connections all help to make installation of the furnace easy and time saving. It features a compact 33 inch design and offers standardized widths for easy coil fit. It can be easily vented with PVC pipe and is design certified for direct and non-direct vent applications. An optional LP kit is available as well for a liquid propane conversion. Thanks to the easily removable slide out blower design, maintenance is a breeze. MRCOOL backs this product with a lifetime heat exchanger warranty and a 10-year parts warranty.