Every space intended for human occupancy shall be provided with ventilation by natural or mechanical means during the periods when the room or space is occupied.
Natural ventilation of an occupied space shall be through windows, doors, louvers, skylights or other openings to the outdoor. Such ventilating openings shall open to the sky or a public street, space, alley, park, highway, yard, court, plaza or other approved space which comply with the requirements of the building code.
Area of ventilating openings
The minimum ventilating opening to the outdoors shall be 4% of the floor area being ventilated.
Where rooms and spaces without opening to the out doors are ventilated through an adjoining room, the unobstructed opening to the adjoining rooms shall be at least 8% of the floor area of the interior room or space, but not less than 2.33 m2. The ventilation openings to the outdoors shall be based on the total floor area being ventilated.
Opening below grade
Openings below grade shall be acceptable for natural ventilation provided the out side horizontal clear space measured perpendicular to the opening is one and one-half times the depth below the average adjoining grade.
Naturally ventilated spaces having contaminants present shall comply with the requirements of Mechanical exhaust will discuss later.
Lp-gas distribution facilities
Lp-gas distribution facilities shall be provided with air inlets and outlets arranged so that air movement across the floor of the facility will be uniform. The total area of both inlet and outlet openings shall be at least 0.7% of the floor area. The bottom of such openings shall not be more than 150 mm above the floor.