Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 9 - Fire Protection Systems › Section 909 - SMOKE CONTROL SYSTEMS › Subsection 909.10 - Equipment

Current through Register 1525, July 5, 2024
Equipment including, but not limited to, fans, ducts,
				  automatic
dampers
and balance
dampers
, shall
				  be suitable for its intended use, suitable for the probable exposure
				  temperatures that the rational analysis indicates and as
approved
by the fire code official. [F]
909.10.1
Exhaust fans.
Components of exhaust fans shall be rated and certified by the manufacturer for
				the probable temperature rise to which the components will be exposed. This
				temperature rise shall be computed by: [F]
T
s =
							 (
Q
c/
mc
) +
							 (
T
a)
(Equation 9-3)
where:
c
= Specific heat of smoke at smoke layer
				  temperature, Btu/lb ·
										°F (kJ/kg . K).
m
= Exhaust rate, pounds per second
				  (kg/s).
Q
c= Convective heat
				  output of fire, Btu/s (kW).
T
a= Ambient
				  temperature, °F (K).
T
s= Smoke
				  temperature, °F (K).
Exception:
Reduced
T
s as calculated based on the assurance
				  of adequate dilution air.
909.10.2
Ducts.
Duct materials and joints shall be capable of withstanding
				the probable temperatures and pressures to which they are exposed as determined
				in accordance with Section 909.10.1. Ducts shall be constructed and supported
				in accordance with the
International Mechanical Code
. Ducts
				shall be leak tested to 1.5 times the maximum design pressure in accordance
				with nationally accepted practices. Measured leakage shall not exceed 5 percent
				of design flow. Results of such testing shall be a part of the documentation
				procedure. Ducts shall be supported directly from fire-resistance-rated
				structural elements of the building by substantial, noncombustible supports.
				[F]
Exception:
Flexible connections (for the purpose
				  of vibration isolation) complying with the
International
Mechanical
Code
, that are constructed of
approved
fire-resistance-rated materials.
909.10.3
Equipment, inlets and
				outlets.
Equipment shall be located so as to not expose uninvolved
				portions of the building to an additional fire hazard. Outside air inlets shall
				be located so as to minimize the potential for introducing smoke or flame into
				the building. Exhaust outlets shall be so located as to minimize reintroduction
				of smoke into the building and to limit exposure of the building or adjacent
				buildings to an additional fire hazard. [F]
909.10.4
Automatic dampers.
Automatic
dampers
, regardless of the purpose for which they
				are installed within the smoke control system, shall be
listed
and conform to the requirements of
approved
, recognized
				standards. [F]
909.10.5
Fans.
In addition to other requirements, belt-driven fans shall
				have 1.5 times the number of belts required for the design duty, with the
				minimum number of belts being two. Fans shall be selected for stable
				performance based on normal temperature and, where applicable, elevated
				temperature. Calculations and manufacturer's fan curves shall be part of the
				documentation procedures. Fans shall be supported and restrained by
				noncombustible devices in accordance with the requirements of Chapter 16.
				Motors driving fans shall not be operated beyond their nameplate horsepower
				(kilowatts), as determined from measurement of actual current draw, and shall
				have a minimum service factor of 1.15. [F]