Lomanco Vents Calculator
All Lomanco attic ventilation product requirements are based on the minimum standard 1/300 rule as set forth by the International Building Code (IBC) and the International Residential Code (IRC). If local code requires the 1/150 rule, please double the requirements. Lomanco foundation ventilation product requirements are based on the 1/150 rule.
Choose your exhaust system and enter area to ventilate. (Attic floor space in square feet.)