Proper Gravity Venting



  •  High and low vent openings must be separated by a minimum of 10 vertical feet.
  • Low vents should be a minimum of 3 ft. high or above snow line.
  • A low vent through an offset adapter is installed at the end of each row, section or basic serial bed.  A vent manifold may be used to connect the ends of multiple sections or rows.
  • The house (roof) vent functions as the high vent as long as there are no restrictions or other vents between the low vent and the house (roof) vent.
  • Roof vent diameter must be a minimum of 3 in., 4 in. recommended.
  • Sch. 40 PVC or equivalent should be used for all high vents.