Attic Ventilation

Attic Ventilation Chart for Agricultural, Commercial and Industrial Use


Values shown are based on a minimum of 1 sq. ft. of Inlet Opening per eave per 1200 sq. ft. of ceiling and a minimum of 1 sq. ft. of Outlet Opening at ridge per 600 sq. ft. of ceiling.


  • SRV-12 Vent (0.92 ft2 opening) vents 550 ft2 of attic.
  • SRV-20 Vent (2.63 ft2 opening) vents 1580 ft2 of attic.

Commercial Vent

  • 9" Throat (7.38 ft2 opening) vents 4400 ft2 of attic.
  • 12" Throat (9.83 ft2 opening) vents 5900 ft2 of attic.