Superior BRT4336 36" Traditional B-Vent Propane Gas Fireplace With Electronic Ignition and White Stacked Refractory Panels support-strap Why is the BTU according

Why is the BTU according to EPA test data smaller than the one advertised

Includes 5 lbs Glass Beads

1 Locking Band Clamp

All Relay Panels are NEMA 4 RATED

Dual overheat protection

Superior BRT4336 36" Traditional B-Vent Propane Gas Fireplace With Electronic Ignition and White Stacked Refractory Panels support-strap Why is the BTU accordingThe BRT4000 B Vent Fireplaces feature multidimensional refractory log arrangement and deep glowing ember bed. An aluminized U tube dual burner provides real wood fire ambiance with 40,000 BTU. The BRT4000 ships smooth faced and include hidden screen pockets, easy access flue damper with safety shut off switch, and refractory. What's Included B Vent Gas Fireplace Transition Collar For vent connection Ceramic Log Pack Volcanic Stone Rock, Pan and Ember