05/15/15
DESIGN NO. ______
SECTION 15872
GRAVITY ROOF VENTILATOR
PART 1 - GENERAL
1.01
2
1.02
1.03
2
1.04
DESCRIPTION OF WORK
A.
Provide gravity roof ventilators and curbs as specified
herein, as shown on the Drawings, and as needed for a
complete and proper installation.
Product specific
requirements are contained herein; Section 15501,
General Provisions for Heating, Ventilating and Air
Conditioning Work, shall be referred to for general
requirements.
RELATED SECTION
A.
Division 3 Sections
B.
Division 7 Sections
C.
Division 9 Sections
D.
Division 15 Sections
SUBMITTALS
A.
Shop Drawings: Include ventilator attachments to curbs
and curb attachments to roof structure.
B.
Coordination Drawings: Roof framing plans and other
details, drawn to scale, on which the following items
are shown and coordinated with each other, based on
input
from
installers
of
the
items
involved:
structural members to which roof curbs and ventilators
will be attached; sizes and locations of roof
openings.
SUPPLEMENTAL QUALITY ASSURANCE
A.
All work shall be in accordance with
Construction Codes and NYC Electrical Code.
the
NYC
PART 2 - PRODUCTS
2.01
GRAVITY VENTILATORS
A.
NYCSCA
Provide standard prefabricated gravity ventilator units
of type and size as shown on the Drawings.
GRAVITY ROOF VENTILATOR 15872 - 1
05/15/15
B.
C.
NYCSCA
DESIGN NO. ______
Roof Ventilators
1.
Provide roof ventilators sized and located where
shown.
Roof ventilators up to 10" in diameter
shall be made of No. 22 gage (.025") aluminum.
Ventilators 12" to 18" diameter shall be No. 20
gage (.032") aluminum with aluminum rivets,
angles,
screens,
and
all
other
items
and
accessories.
Screens shall be 3/4" mesh No. 18
gage aluminum wire cloth.
2.
Roof ventilators shall be the equal of G.C.
Breidert
Co.'s
"Air-X-Hauster",
Triangle
Engineering Co.'s "Mastervent", United Enertech or
PennBarry complying with the Specification.
Louvered Penthouses
1.
Provide a louvered penthouse constructed of
extruded aluminum on the roof at each location as
shown. Penthouse shall be of the size indicated,
and shall be designed to fit the rectangular
outside air intake or exhaust opening through the
roof curb.
2.
Penthouse shall consist of four storm proof
louvered sides and solid pitched roof, framed and
reinforced, and constructed entirely of aluminum.
Penthouses for curbs whose longer side is 4' or
less (inside dimension) shall be constructed with
mitered corners heliarc welded and reinforced by
2" x 2" x 1/4" inside corner angles. Larger size
penthouses shall be constructed with corner posts
1/8" thick. Frames and blades shall be fabricated
of extruded sections, 1/8" in thickness of 6063-T5
aluminum alloy. Blades shall be 4" in width and
spaced on 41/2" (maximum) centers.
The lower
portion of each blade shall overlap the upper
portion of the blade beneath it a sufficient
distance to prevent the entrance of snow or rain
driven horizontally at the penthouse. The amount
of this overlap is subject to approval by the
Authority and shall be dimensioned on the Shop
Drawings.
Louver sections shall be reinforced
vertically with 2" x 2" x 1/4" angles from the
base to the roof, spaced on a maximum of 4'
centers.
A bird screen of not less than No. 16
gage expanded aluminum or No. 12 gage, 3/4" mesh
aluminum cloth fitted in a frame, shall be secured
to the inside of each louver section. Roof shall
be
1/8"
5005-H14
sheet
aluminum
suitably
reinforced on 4' (maximum) centers and insulated
with membrane undercoating.
GRAVITY ROOF VENTILATOR 15872 - 2
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DESIGN NO. ______
3.
Approved Manufacturers:
Alpine Sheet Metal & Ventilating Co.
Arrow Louver & Damper Co.
Carnes Co.
Hugh Richards Associates, Inc
2.03
2
PREFABRICATED ROOF CURBS
A.
Provide manufacturer's standard shop-fabricated units
modified if necessary to comply with requirements.
B.
Fabricate structural framing for units of structural
quality sheet steel (ASTM A 570, Grade 40), formed to
profiles
indicated
or,
if
not
indicated,
to
manufacturer's standard profiles for coordination with
roofing, insulation and deck construction.
Include
deck
flanges
with
offsets
to
accommodate
roof
insulation. Weld corners and seams to from watertight
units.
1.
C.
Reinforce continuous runs of over 3'-0" length, by
inserting welded stiffeners of heavy gauge with
flanges as required to provide sufficient rigidity and
strength to withstand maximum lateral forces in
addition to superimposed vertical loads.
D.
Sloping Roof Decks: For deck slopes of 1/4" per foot
and more, fabricate support units to form level top
edge.
E.
Gage and Height: Fabricate units of metal gage and to
height above roof surface as indicated on the
Drawings.
Where gage or height are not indicated,
fabricate units of 14 ga metal and nominal height of
14".
F.
Provided treated wood nailer, not less than 15/8" thick
and of width indicated on the Drawings, but not less
than width of support wall assembly.
Anchor nailer
securely to top of metal frame unit.
1.
G.
NYCSCA
Clean and paint units with manufacturer's standard
rust-inhibitive metal primer paint.
(Refer to
Section 09900: Painting).
Provide lumber pressure treated with water-borne
preservatives for "above ground" use, complying
with AWPB LP-2.
Insulate units inside structural support wall with
rigid glass fiber insulation board of approximately 3
GRAVITY ROOF VENTILATOR 15872 - 3
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DESIGN NO. ______
lb density and 11/2" minimum thickness, except as other
wise indicated on the Drawings.
1
H.
Provide support
galvanized sheet
lower edges.
construction to
indicated on the
liner where shown, formed of 22 ga
metal, mill phosphatized, flanged at
Extend support liners through deck
coordinate with ductwork below as
Drawings.
I.
Metal Deck Reinforcement: Where indicated as integral
part of support units, provide channel-shaped metal
deck closure strips to reinforce opening through metal
decking.
Fabricate strips from 14 ga metal to match
metal and finish of curb units, except as otherwise
indicated on the Drawings.
J.
Curbs
shall
Manufacturer.
be
the
product
of
the
Ventilator
PART 3 – SUPPLEMENTAL EXECUTION
3.01
INSTALLATION
A.
Coordinate ventilator work with work of roofing, as
necessary for proper interfacing.
B.
Ductwork: Connect ducts to ventilators in accordance
with manufacturer's installation instructions and as
shown on the Drawings.
Provide access door in duct
below ventilator to service damper.
Per ASHRAE 90.12010 as modified by Appendix A of the 2014 NYCECC,
systems shall be equipped with Class 1 motorized
dampers (with a leakage not exceeding 4 cfm/SF at 1.0”
w.c. when tested in accordance with AMCA 500D) that
will automatically shut when the systems or spaces
served are not in use. Gravity (non-motorized) exhaust
or relief dampers are acceptable in buildings less than
three stories in height.
Gravity (non-motorized)
dampers are acceptable in systems with a design
spill/relief exhaust capacity of 300 cfm or less.
Gravity dampers shall have a maximum leakage rate of 20
cfm/SF at 1.0” w.c. when tested in accordance with AMCA
500D. Gravity dampers smaller than 24 inches in either
dimension shall be permitted to have a leakage of 40
cfm/SF at 1.0” w.c. when tested in accordance with AMCA
500D. Provide ventilators with the damper types as
shown on the Drawings. Solder bottom joints and up 2"
of side joints of duct under roof ventilator to retain
any moisture entering ventilator.
C.
Roof Curbs: Each roof ventilator shall be installed on
the
manufacturer’s
pre-fabricated
curb.
Duct
connection for the ventilator shall be extended to the
3
2
NYCSCA
GRAVITY ROOF VENTILATOR 15872 - 4
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DESIGN NO. ______
top of the wood sill and flanged over. Ventilator base
shall fit over the curb opening and shall be made
airtight by the use of a heavy roofing felt gasket.
The base shall be secured to the wood sill with
stainless steel lag screws.
2
4
3.02
D.
Louvered
Penthouses:
fabricated roof curb.
Provide
manufacturer’s
pre-
E.
Remove shipping bolts and temporary supports within
ventilators. Adjust dampers for free operation.
F.
Provide seismic bracing/restraints as required.
Contractor’s Professional Engineer shall detail all
ventilator seismic bracing and restraints and submit
calculations.
FIELD QUALITY CONTROL
A.
Testing: After installation of ventilators has been
completed, test each ventilator to demonstrate proper
operation of units at performance requirements.
When
possible, field correct malfunctioning units, and then
retest to demonstrate compliance.
Replace units that
cannot be satisfactorily corrected.
END OF SECTION
MM:BB
05/15/15
Notes to Specifier (Delete from Specification)
1.
Delete if deck is not metal, or if not necessary.
2.
Coordinate
with
Architectural/Structural
disciplines
regarding how ventilators are to be supported (i.e. poured
concrete curbs or pre-fabricated curbs). Coordinate curb
sizes with ventilator dimensions. Any poured concrete curb
details shall be shown on the structural drawings. Edit
section as required.
3.
Designer shall specify appropriate damper type in the
Schedule of Equipment on the Drawings. Show the control of
any automatic motorized dampers on the Drawings.
4.
Section 15503 is to be utilized if the project involves
construction of a New Building or Addition to building in
Seismic Design Category C or D. Section 15503 is also to be
utilized if project involves retrofit work in Existing
Buildings in Seismic Design Category C or D constructed
after LL17/1995 went into effect. Section 15503 is not
required for retrofit work on Existing Buildings constructed
NYCSCA
GRAVITY ROOF VENTILATOR 15872 - 5
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DESIGN NO. ______
prior to the effective date of LL17/1995 and for any
buildings in Seismic Design Category B. Include Section
15503 in the Construction Documents as required.
* * *
NYCSCA
GRAVITY ROOF VENTILATOR 15872 - 6
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DESIGN NO. ______
LIST OF SUBMITTALS
SUBMITTAL
DATE SUBMITTED
DATE APPROVED
Product Data:
______________
_____________
______________
_____________
1. Manufacturers Product Data
2. Installation Instructions
Shop Drawings:
1.
2.
3.
4.
5.
Assembly-type
Dimension Drawings
Mounting Details
Location
Ventilator and Curb Attachments
Coordination Drawings:
______________
_____________
* * *
NYCSCA
GRAVITY ROOF VENTILATOR 15872 - 7