The Ontario Building Code | Fire Dampers Waived
3.1.8.8. Fire Dampers Waived
(1) Fire dampersneed not be provided in noncombustible branch ducts that have a melting point above 760°C and that penetrate a required fire separation provided the ducts,
(a) serve only air-conditioningunits or combined air-conditioning and heating units discharging air not more than 1 200 mm above the floor and have a cross-sectional area not more than 130 cm2, or
(b) are connected to exhaust duct risers that are under negative pressure and in which the air flow is upward as required by Article 3.6.3.4. and are carried up inside the riser not less than 500 mm.
(2) A continuous noncombustible duct penetrating a vertical fire separation not required to have a fire-resistance ratingneed not be equipped with a fire damper at the fire separation.
(3) A noncombustible duct that penetrates a horizontal fire separation not required to have a fire-resistance rating need not be equipped with a fire damper at the fire separation.
(4) A noncombustible duct that penetrates a fire separation that separates avertical service space from the remainder of the buildingneed not be equipped with a fire damper at the fire separation provided,
(a) the duct has a melting point above 760°C, and
(b) each individual duct exhausts directly to the outside at the top of the vertical service space.
(5) A continuous noncombustible duct having a melting point above 760°C that penetrates a vertical fire separation as required by Sentence 3.3.1.1.(1) between suites of other than care, care and treatment, detentionor residential occupancy need not be equipped with a fire damper at the fire separation.
(6) A duct that serves commercial cooking equipment and penetrates a required fire separation shall be,
(a) enclosed in a vertical service space that conforms to Sentence 3.6.3.1.(1),
(b) enclosed in a horizontal service space that conforms to Sentence 3.6.4.2.(1), or
(c) equipped with a fire damper, specifically designed for such use, at the fire separation.
(7) In elementary and secondary schools, a continuous noncombustible duct having a melting point above 760°C that pierces a fire separation having a fire-resistance rating of 30 min need not be equipped with a fire damper at the fire separation.
(8) In a Group B, Division 3 occupancy that contains sleeping accommodation for not more than 10 persons and not more than six occupants require assistance in evacuation in case of an emergency and which is equipped with a fire-alarm system, a duct need not be provided with a fire damper at a fire separation provided duct-type smoke detectors have been installed to control smoke circulation as described in Article 3.2.4.13.