Ventilation Building Codes

Disclaimer: The Information contained on this web page has been collected and presented as a guide.  It should be used as a guide only and should not be relied upon as the sole source of information relating to ventilation requirements or legal requirements in any state or municipality. No warranty, either express or implied, is made with respect to the information contained herein. For additional information contact the specific state or municipality to obtain specific technical or legal ventilating requirements that may apply. Empire Ventilation Equipment Co., Inc. is not responsible for any loss, inconvenience, damage (whether special or consequential) or claims arising out of the use of the information contained on this page.


420.3.13 Ventilating and air-conditioning systems.

420.3.13.1 Mechanical equipment shall be defined as
equipment utilized in air-conditioning, heating, ventilating
systems and associated electrical, electronic and
pneumatic components required for the mechanical
equipment to provide the function intended by the application
of the equipment. New and existing equipment
replacements shall comply with these requirements.

420.3.13.2 Mechanical equipment shall be installed in a
designated equipment room(s), or in a space(s) located in
an attic(s).

420.3.13.3 If the unit serves only one room it may be
located above the ceiling and shall be accessible through
an access opening in accordance with this code. Access
panels are not required for lay-in ceiling installations,
provided the service functions are not obstructed by
other above-ceiling construction, such as electrical conduits,
piping, audio visual cabling and like equipment
components or supports.

420.3.13.4 Ventilation shall be provided by mechanical
means in all rooms in new facilities and in all renovated
or remodeled rooms. The minimumair quantities and filtration
efficiencies shall be met as set forth in Table

420.3.13.7 for those spaces that are listed.

420.3.13.5 For spaces listed in the minimum ventilated
rate table, central station type air-handling equipment
shall be used. Package terminal air-conditioning units or
fan coils maybe used to serve resident rooms and shall be
provided with 20-percent filters minimum.

420.3.13.6 System designs utilizing fan coil or package
terminal air-conditioning units shall have the outdoor air
ventilation damper permanently closed. The ventilation
requirement shall be satisfied by a central station type air
handling unit provided with a 30-percent filter minimum
or as required by the listed space served. Spaces designated
for the exclusive use of physical plant personnel
need not comply with this requirement.

420.3.13.7 Administrative and other staff-only areas
shall be provided with outside air at the minimum rate of
20 cfm (9.43 L/s) per person, and the central system shall
have a minimum of 30 percent ASHRAE dust spot efficiency

420.3.13.8 All outdoor air intakes shall be located a minimum
of 3 feet (0.91 m) above surrounding surfaces and
a minimum of 10 feet (3.05 m) horizontally from any
exhaust air or plumbing ventilator.

420.3.13.9 All filters in systems in excess of 1000 cfm
(28.32 m 3 /min) capacity shall be installed with differential
pressure gauges. The filter gauge shall have the range
of acceptable filter operation clearly and permanently

420.3.13.10 Filter housings for 80-percent efficiency filters
shall be fully gasketed and sealed with mechanical
latching devices capable of exerting and maintaining a
continuous, uniform sealing pressure on the filter media
when in the latched, closed position.

420.3.13.11 The transfer of air quantities through one
space to an adjacent space is not permitted except that the
transfer of air to maintain space relative pressure by the
under cutting of doors is permitted. The maximum
allowable air quantity for door undercuts shall be 75 cfm
(35.38 L/s) for single door widths up to 44 inches (1117

420.3.13.12 Space relative pressure requirements shall
be maintained throughout the entire system control range
where variable volume systems are utilized.

420.3.13.13 Spaces having exhaust hoods shall have sufficient
make-up supply air such that the required pressure
relationship will not be affected by the operation of
the hood.

420.3.13.14 All supply, return and exhaust ventilation
fans shall operate continuously. Dietary hood, laundry
area, administrative areas that are separated from all resident
areas and support areas and maintenance area supply
and exhaust fans shall be exempted from continuous

420.3.13.15 Cooling coil condensate shall be piped to a
roof drain, floor drain or other approved location.

420.3.14 Exhaust.

420.3.14.1 Exhaust fans and other fans operating in conjunction
with a negative duct system pressure shall be
located at the discharge end of the system. Fans located
immediately within the building located at the end of all
exhaust ducts shall be permitted. Existing,
nonconforming systems need not be brought into compliance
when equipment is replaced due to equipment

420.3.14.2 Exhaust hoods in food preparation areas shall
be listed or certified by a nationally recognized testing
laboratory (NRTL).

420.3.15 Ducts.

420.3.15.1 All new facility construction shall have
totally ducted supply, return, exhaust and outside air systems
including areas of all occupancy classifications.

420.3.15.2 In new construction, duct system risers penetrating
more than one floor shall be installed in vertical
fire-rated shafts. Horizontal offsets of the risers shall not
be allowed. Fire/smoke dampers shall be installed at duct
penetrations of the chase. Existing nonconforming systems
shall be brought into compliance when remodel or
renovation work is proposed.

420.3.16 Fan and damper control during fire alarm.

420.3.16.1 During a fire alarm, fan systems and fan
equipment serving more than one room shall be stopped
to prevent the movement of smoke by mechanical means
from the zone in alarm to adjacent smoke zones.

420.3.16.2 Air-handling and fan coil units serving exit
access corridors for the zone in alarm shall shut down
upon fire alarm.

420.3.16.3 Smoke or fire/smoke dampers shall close
upon fire alarm and upon manual shutdown of the associated
supply, return or exhaust fan.



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Eveco Ventilators
Syphon Ventilators
Turbine Ventilators
1/2“ Mesh Screens
Insect Screens
Dampers For Syphon or Eveco
Dampers For Turbine Ventilators
Adjustable Bases
Economy Bases
Standard Mounting Bases
• Flat Bases
• Ridge Roof Bases
• Curb Bases
• Slope Roof Base
Booster Fans
Cast Aluminum Ventilators
Extruded Aluminum Ventilators
Flange Extruded Ventilators
Flush-Flange Louvers
Roof Louvers
Strip Ventilators
Spring Register
Repair Kit
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