Heating Capacity*: Up to 1,250 Sq. Ft.BTU/Hr. Input (NG/LP): 13,000 to 25,000 (50% turndown)P4 Efficiency: 65.74% (NG) 66.88% (LP)Steady State Efficiency Up to 76.11% (NG) Up to 77.31% (LP)Weight: 165 lbs. (75 kg).Glass Viewing Area: Tempered Glass, 40-3/8” W x 13-5/8” H, 548 Sq. In.