Flare-FF-50 vent calculation example based on the manual: Vent path from Survey: 3 ft up from the fireplace 45 elbow 1ft 45 elbow up 15 ft vertical up Vertical cap Y vertical calculation A – First Flue length = 3 = 3 ft B – Vertical
The pebbles size will vary and are approximately 2 - 3 inches. See below picture for a better perspective of the pebbles. The stones size will vary and are approximately 1 1/2" - 3".
For Fireplaces sized 30" up to 70" - a Minimum of 3' rise off the top of the fireplace is required before any elbow For Fireplaces sized 80" up to 100" - a Minimum of 6' rise off the top of the fireplace is required before any elbow