Greenheck GRS-15 User Manual

Gravity Ventilators

Models FGI, FGR, GRS, WIH, WRH and RGU

Intake and Relief

June

2010

Gravity Ventilators

Fabra Hood

Louvered Penthouse

4

Designed for intake or relief applications, the Fabra Hood
models FGI or FGR offer many important advantages over other
gravity roof ventilators. It is superior in load bearing strength,
weather-resistance, dimensional flexibility and appearance.

Models FGI and FGR ......... . . . .......... . . . .......... . 4-7

Dimensions and Performance Data ....... . . . ....8-13

14 Spun Aluminum

For natural gravity or positive pressure systems, intake model
GRSI or relief model GRSR, offers excellent performance and
durability. Featuring an exceptional low silhouette design and
rugged construction this model is both efficient and economical.

Model GRS ........ . . . .......... . . . .......... . . . .......... . . 14

Dimensions and Performance Data ....... . . . .. 14-15

16

Upblast Ventilator

The WIH intake or WRH relief penthouse units offer an
aesthetically pleasing design. This flexible design allows for
units to be shipped in pre-assembled sections that can be easily
assembled without special tools.

Models WIH and WRH ......... . . . .......... . . . .......... 16

Dimensions and Performance Data ....... . . . .. 16-17

18

Model RGU is designed for use as an outlet on vertical high
velocity exhaust systems. The RGU can be furnished with or
without the curb cap for mounting directly on round stacks.

Model RGU . . . .......... . . . .......... . . . .......... . . . ...... 18

Dimensions and Performance Data ....... . . . ...... 18

All Ventilator Specifications ........ . . . .......... . . . .. 19-20

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Quick Delivery and
Quick Build Programs

Greenheck’s Quick Delivery program
provides many options to help you

meet your project’s schedule. Stocking
warehouses and distribution centers around the
world ensure same-day pickup and same-day
shipment for orders in by 2 p.m. (CST). Hundreds
of custom products can be manufactured through
Quick Build in just days.

For available options and accessories please refer
to the Greenheck Stock & Quick Build Catalog.

Outstanding Customer Service

Greenheck’s experienced staff is ready to answer your questions
and delivers solutions. Our representatives have a wealth
of industry and product knowledge, they maintain the latest
information and can process orders directly to our factory.

Count on the personal service and expertise from our national
and international representative organizations. To locate the
Greenheck representative nearest you, call 715-359-6171 or visit
our Web site at www.greenheck.com.

Leading Edge
Technical Support

When product and IOM
(Installation, Operation

and Maintenance Manual)
information is needed, our products are supported
by the industry’s best product literature, electronic
media and Computer Aided Product Selection (CAPS)
program. You’ll also find this information on our
Web site at www.greenheck.com.

Our national and international representative
organization provide personal service and expertise.
To locate your nearest Greenheck representative,
call 715-359-6171 or visit our Web site at

www.greenheck.com.

World Class Manufacturing

Greenheck’s skilled production workers use cost-effective
machines and unique dies designed and built by our own
engineers to add innovative features and greater strength to
our gravity ventilators. Our advanced manufacturing processes
and quality control procedures always ensure the highest
product quality. And just to be sure you get the peace-of­mind you expect when you specify Greenheck, our assembly
inspectors test run and monitor every unit before it leaves
the factory.

3

Fabra Hood
Models FGI and FGR

Fabra Hoods are designed
for intake (model FGI) or relief
(model FGR) applications. The Fabra
Hood design offers many important
advantages not found in other gravity roof
ventilators. It’s design is superior in appearance,
load-bearing strength, weather-resistance and
dimensional flexibility.

Appearance

The clean lines and uniform structural design of the
Fabra Hood complement any building’s appearance.
The Fabra Hood is designed with a low profile to
mount close to the roofline. The result is minimum
impact on the building silhouette.

Strength and Weather‑Resistance

These hoods are strong enough to handle the snow
loads found in even the harshest of northern climates
and they have proven their ruggedness. The key to
the Fabra Hood’s strength and rigidity is in the design
of the arched hood panels. Each panel provides its
own structural support and is formed with interlocking
edges. The result is a strong, rigid shell without the
obstruction and performance losses of excessive
internal support braces. The interlocking ribs also
create tight, weather-resistant joints. No caulking or
caps are required to seal out rain and snow.

Third Party Certified for High Wind

Miami Dade, Notice of Acceptance (NOA) - 09-0511.03
Florida Product Approval (FLPA) - FL12917
All standard models are hurricane certified

• Highest industry rating

• Fans are certified for static and cyclic wind loading
and missile impact

• Designed to withstand wind loads of up to
150 mph (241 k)

• No tie downs are needed

• Installation/mounting details are provided

Performance

The rounded inner surfaces of the Fabra Hood’s
arched panels promote a smooth, uninterrupted
flow of air to reduce pressure losses. Cataloged
performance data is assured through extensive air
testing of both ducted and non-ducted installations
with standard birdscreens in place. Intake and relief
units differ in size and performance. It is important
to note that the “free area” (the opening surrounding
the throat) is larger for intake hoods. This larger free
area (twice the area of the throat) limits the entry of
airborne debris and moisture by creating lower intake
air velocities. Since relief units are not affected by
velocity considerations, free area is equal to throat
area. Consequently, the smaller overall dimensions
of relief units result in lower cost.

Broad Range of Sizes

Model FGI (intake) and FGR (relief) are available in
throat sizes ranging from a minimum of 8 inches

(203 mm) wide by 8 inches (203 mm) long to a maximum

of 72 inches (1829 mm) wide by 180 inches (4572 mm)
long. The complete range of standard suggested
throat sizes is shown on pages 8-13. Other sizes are
also available in increments of one inch within the
limits shown.

Shipping

Most Fabra Hoods ship assembled until they are
too large to fit in a semitrailer. See page 8-13 for
specific dimensional data.

Assembly

With the Fabra Hood’s interlocking rib design, hoods
of long lengths can be constructed on the jobsite.
Where the appearance of a single unit is desired,
large roof openings can be covered using a single
hood. This also represents a cost savings in working
with a single roof penetration. Neither special tools
nor training are required for assembly.
See page 7 for details.

4

Fabra Hood
Construction Features

Precision Formed Locking Rib System

Strength, weather tightness and adjustable lengths
are the primary advantages of the Fabra Hood’s
arched, interlocking hood panels. A single precision
roll forming operation creates the rib, the adjacent
channel and the arch. All three features work in
combination for rigidity and efficient water drainage.

Fabra Hoods are
available with
hood panels and
bases constructed
of aluminum or
galvanized steel
as specified.

1

Accessibility

Fabra Hoods are designed for ease of access to
allow inspection and maintenance of screens, filters
and dampers. Removal of the two bolts on each
support angle permits the hood to be lifted off the
base. This construction also allows for a hinged
function. By removing bolts on the support angle on
one side of the unit’s panel length, the hood can swing
up and over to lie on the roof deck.

NOTE: For safety, it is not recommended to use this
hinging function with larger hoods or to prop any
hood part way open. Care should be taken to avoid
handling an unbolted hood in strong winds, especially
with larger size units.

5

2

3

4

Hood panels

1

Panels are arched and precision roll formed
for strength and weather tightness. The design
and construction provides sufficient structural
strength to allow inlet and outlet areas to be
virtually unobstructed by support members.

Birdscreens

2

Standard birdscreens are constructed of 1⁄2-inch

(13 mm) galvanized steel mesh for minimum

restriction of airflow.

Support members

3

Heavy-gauge galvanized steel support members
provide additional structural strength as well as
a hood/base interface. On larger hoods, truss
braces are added for increased strength.

Standard base

4

Standard base height is 5 inches (127 mm). Bases
include prepunched mounting holes for ease of
installation. The curb cap is 6 inches (152 mm)
larger than the throat size to minimize airflow
restrictions. Reinforced steel hood support
members are securely attached to the base and
direct hood loads to the roof curb. 12-inch (305

mm)

bases are optional. See page 6 for details.

Vertical end panels

5

Vertical panels are fully locked into the hood
end panels.

5

Fabra Hood
Construction Options

Hood Insulation

Aluminum Birdscreen
(Galvanized Standard)

5-inch Base

(127 mm)

12-inch tall bases

12-inch (305 mm) bases are recommended for intake
applications to prevent moisture entry and for all
applications where rain or snow may accumulate on
the roof deck. On larger size units, a 12-inch (305 mm)
base will provide more clearance space from the roof
deck and allow for better airflow.

Fiberglass hood insulation

Either ½-inch (13 mm) or 1-inch (25 mm) insulation
can be factory applied to the underside of the
hood to prevent condensation. Insulation is
also factory applied to individual panels of large
unassembled units.

Aluminum birdscreen

¾ x 1¼ inch (19 mm x 32 mm) diamond shape is
available in lieu of standard galvanized birdscreen.

Insect Screen

Filters

12-inch

(305 mm)

Tall Base Option

Tie-down points

Heavy-gauge galvanized steel tie-down points are
available as cable attachment points at the ends
of each hood support rail and prevent damage to
the Fabra Hood in locations where unusually strong
winds occur.

Special coatings

Several options are available for decorative or
protective purposes.

Factory primed for field application of final finish.

Baked enamel finish is applied to exterior surfaces

only to match or complement a building's color.

Protective coatings that include Greenheck’s

Permatector™ (a thermosetting polyester urethane)

are also available. Protective coatings are applied
to all surfaces. Refer to the Performance Coatings
catalog for complete coating options.

AluminumInsectScreen

A fine mesh aluminum insect screen tightly fitted
to the top of the throat, is available to prevent the
entry of insects. (This is in addition to the standard
birdscreen and is available on factory assembled units
only.) Use the curves on the graph below to determine
the static pressure drop for units with insect screen.

0.40

0.35

0.30

0.25

0.20

0.15

0.10

Static Pressure Drop (in. wg)

0.05

0.00
0 200 400 600 800 1000 1200

Aluminum Insect Screen

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Throat Ve locity (ft./min)

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Filters

Two-inch aluminum filters are available on model FGI
(intake) for applications where foreign material must
be removed from the airstream. Use the curves on the
graph below to determine the static pressure drop for
units with filters.

Filters

0.60

0.50

0.40

0.30

s

n

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0.20

Static Pressure Drop (in. wg)

0.10

0.00
0 200 400 600 800 1000 1200

D

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Throat Ve locity (ft./min)

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