Where required by this code or otherwise installed, smoke and heat vents or mechanical smoke exhaust systems and draft curtains shall conform to the requirements of this section.
Exceptions:
1. Frozen-food warehouses used solely for storage of Class I and II commodities where protected by an automatic sprinkler system in accordance with Section 903.3.1.1.
2. Where areas of buildings are equipped with early suppression fast-response (ESFR) sprinklers, automatic smoke and heat vents shall not be required within these areas.
Exceptions:
1. Frozen-food warehouses used solely for storage of Class I and II commodities where protected by an automatic sprinkler system in accordance with Section 903.3.1.1.
2. Where areas of buildings are equipped with early suppression fast-response (ESFR) sprinklers, automatic smoke and heat vents shall not be required within these areas.
Smoke and heat vents shall be installed in the roofs of buildings or portions thereof occupied for the uses set forth in Sections 910.2.1 and 910.2.2. Vents shall be installed at the top of a closed shaft in accordance with Section 708.12.1.
The design and installation of smoke and heat vents and draft curtains shall be as specified in Sections 910.3.1 and Table 910.3.
TABLE 910.3 REQUIREMENTS FOR DRAFT CURTAINS AND SMOKE AND HEAT VENTSa
TABLE 910.3 REQUIREMENTS FOR DRAFT CURTAINS AND SMOKE AND HEAT VENTSa
| OCCUPANCY GROUP AND COMMODITY CLASSIFICATION | DESIGNATED STORAGE HEIGHT (feet) | MINIMUM DRAFT CURTAIN DEPTH (feet) | MAXIMUM AREA FORMED BY DRAFT CURTAINS (square feet) | VENT AREA TO FLOOR AREA RATIOc | MAXIMUM SPACING OF VENT CENTERS (feet) | MAXIMUM DISTANCE FROM VENTS TO WALL OR DRAFT CURTAINb (feet) |
| Group F-1 | ‒ | 0.2 × Hd but ≥ 4 | 50,000 | 1:100 | 120 | 60 |
| High-piled (see Section 910.2.2) Class I-IV commodities (Option 1) | ≤ 20 | 6 | 10,000 | 1:100 | 100 | 60 |
| > 20 ≤ 40 | 6 | 8,000 | 1:75 | 100 | 55 | |
| High-piled Storage (see Section 910.2.2) Class I-IV commodities (Option 2) | ≤ 20 | 4 | 3,000 | 1:75 | 100 | 55 |
| > 20 ≤ 40 | 4 | 3,000 | 1:50 | 100 | 50 | |
| High-piled Storage(see Section 910.2.2) High hazard commodities (Option 1) | ≤ 20 | 6 | 6,000 | 1:50 | 100 | 50 |
| > 20 ≤ 30 | 6 | 6,000 | 1:40 | 90 | 45 | |
| High-piled Storage (see Section 910.2.2) Class High hazard commodities (Option 2) | ≤ 20 | 4 | 4,000 | 1:50 | 100 | 50 |
| > 20 ≤ 30 | 4 | 2,000 | 1:30 | 75 | 40 |
| For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2. |
| a. Requirements for rack storage heights in excess of those indicated shall be in accordance with the New York City Fire Code. For solid-piled storage heights in excess of those indicated, an approved engineered design shall be used. |
| b. Vents adjacent to walls or draft curtains shall be located within a horizontal distance not greater than the maximum distance specified in this column as measured perpendicular to the wall or draft curtain that forms the perimeter of the draft curtained area. |
| c. Where draft curtains are not required, the vent area to floor area ratio shall be calculated based on a minimum draft curtain depth of 6 feet (Option 1). |
| d. H is the height of the vent, in feet, above the floor. |
Automatic smoke and heat vents containing heat-sensitive glazing designed to shrink and drop out of the vent opening when exposed to fire shall fully open within 5 minutes after the vent cavity is exposed to a simulated fire, represented by a time-temperature gradient that reaches an air temperature of 500°F (260°C) within 5 minutes.
Where installed in buildings provided with an automatic sprinkler system in accordance with Section 903.3.1.1, smoke and heat vents shall be designed to operate automatically.
Where installed in buildings not provided with an automatic sprinkler system, smoke and heat vents shall operate automatically by actuation of a heat-responsive device rated at between 100°F (38°C) and 220°F (104°C) above ambient.
Exception: Gravity-operated drop-out vents complying with Section 910.3.2.1.
Exception: Gravity-operated drop-out vents complying with Section 910.3.2.1.
The effective venting area shall not be less than 16 square feet (1.5 m2) with no dimension less than 4 feet (1219 mm), excluding ribs or gutters having a total width not exceeding 6 inches (152 mm).
Smoke and heat vents shall be located 20 feet (6096 mm) or more from adjacent lot lines and fire walls and 10 feet (3048 mm) or more from fire barriers. Vents shall be uniformly located within the roof in the areas of the building where the vents are required to be installed by Section 910.2, with consideration given to roof pitch, draft curtain location, sprinkler location and structural members.
Where required by Table 910.3, draft curtains shall be installed on the underside of the roof in accordance with this section.
Exception: Where areas of buildings are equipped with early suppression fast-response (ESFR) sprinklers, draft curtains shall not be provided within these areas. Draft curtains shall only be provided at the separation between the ESFR sprinklers and the conventional non-ESFR sprinklers.
Exception: Where areas of buildings are equipped with early suppression fast-response (ESFR) sprinklers, draft curtains shall not be provided within these areas. Draft curtains shall only be provided at the separation between the ESFR sprinklers and the conventional non-ESFR sprinklers.
Draft curtains shall be constructed of sheet metal, lath and plaster, gypsum board or other approved materials that provide equivalent performance to resist the passage of smoke. Joints and connections shall be smoke tight.
The location and minimum depth of draft curtains shall be in accordance with Table 910.3.
Where approved by the department, engineered mechanical smoke exhaust shall be an acceptable alternate to smoke and heat vents.
Exhaust fans shall be uniformly spaced within each draft-curtained area and the maximum distance between fans shall not be greater than 100 feet (30 480 mm).
Fans shall have a maximum individual capacity of 30,000 cfm (14.2 m3/s). The aggregate capacity of smoke exhaust fans shall be determined by the equation:
where:
C = A × 300
(Equation 9-4)
where:
| C | = | Capacity of mechanical ventilation required, in cubic feet per minute (m3/s). |
| A | = | Area of roof vents provided in square feet (m2) in accordance with Table 910.3. |
Mechanical smoke exhaust fans shall be automatically activated by the automatic sprinkler system or by heat detectors having operating characteristics equivalent to those described in Section 910.3.2. Individual manual controls of each fan unit shall also be provided.
Wiring for operation and control of smoke exhaust fans shall be connected ahead of the main disconnect and protected against exposure to temperatures in excess of 1,000°F (538°C) for a period of not less than 15 minutes. Controls shall be located so as to be immediately accessible to the fire service from the exterior of the building and protected against interior fire exposure by not less than 1-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 712, or both. The location of manual controls is subject to the approval of the Fire Commissioner.
Supply air for exhaust fans shall be provided at or near the floor level and shall be sized to provide a minimum of 50 percent of required exhaust. Openings for supply air shall be uniformly distributed around the periphery of the area served.