Applications

G and GB models

High Wind and Hurricane - G and GB

Greenheck is leading the High Wind Standard for roof top fans and ventilators. Forceful winds and wind-borne debris are the cause of most hurricane damage. Hurricane winds start at 75 mph. At speeds over 150 mph, wind can exert a force of 75 pounds per square foot of pressure or over 900 pounds on a fan and curb. Forceful winds are not the only problem, wind-borne debris can also cause detrimental effects to objects and structures. High winds and extreme forces are the cause of most storm damage. By analyzing calculations, computer simulations, actual testing, and other standards— Greenheck developed the High Wind Standard..

Protocols designed

to protect against wind borne debris and severe wind loads:

U.S. continent

averaged

tornado frequency.

Atlantic, Gulf and Pacific history of major hurricane tracks.

Structural

A static load that is 1..5 times the design load (91..5 pounds per square foot of pressure) is applied

both positively and negatively to simulate wind force loads in each direction. Structural Performance

Performance Load

per Dade County Protocol TAS-202 (ASTM-E330)..

 

 

 

 

Greenheck worked with Miami-Dade County to outline a High Velocity Hurricane Zone standard for

Miami-Dade County

rooftop fans. Greenheck model USGF was the first rooftop fan certified and approved by the Miami-

Dade Building Code Compliance office and Texas Department of Insurance for use in hurricane

Test Protocols

zones. Models G and GB have been certified by an independent third party to the ASTM E-330 Static

 

Pressure Difference Standard, Florida Building Code Test Protocol TAS-201 (large missile impact),

 

202 (static pressure difference) and 203 (cyclic pressure) Static Pressure Difference..

 

 

Miami-Dade NOA

The certifications can be viewed on the Miami-Dade County website under the NOA numbers listed

below. Models G and GB are the first downblast aluminum fans in the industry that have received

Numbers

a Miami-Dade NOA for high wind (150 mph) and hurricane zones. Miami-Dade NOA 09-0624.09 for

 

models G and GB..

 

 

Florida Product

Florida Product Approval ensures that products which have been approved can be used anywhere in

the State of Florida which are not governed by the Miami-Dade County high wind regulations. More

Approval

information can be found on the Florida Building Code website. Florida Product Approval FL13225.1

 

for models G and GB

 

 

 

Structural calculations performed by a licensed Professional Engineer (P..E..) on models G and GB

State Licensed

include Finite Element Analysis (FEA) and a stamped P..E.. report of the fans compliance to ASCE

7-02 Minimum Design Loads for Buildings and Other Structures Standard and the Florida Building

P..E.. Calculations

Code.. The ASCE 7-02 Standard meets the IBC, Florida and Miami-Dade codes.. The models have

 

 

been proven to withstand winds in excess of 150 mph (75 psf).

 

 

Computational Fluid

All Greenheck high wind models have been analyzed using Computational Fluid Dynamics (CFD).

CFD is computer software designed to simulate the flow of high speed (150 mph) winds over the

Dynamics (CFD)

surface of objects. The software records the force profile exerted on the fan so it can be utilized

 

in Finite Element Analysis (FEA)..

 

 

Finite Element

Utilizing the results from CFD analysis, Greenheck can accurately predict the stress, strain,

and deflection resulting from high wind loads. Greenheck high wind units have been proven

Analysis (FEA)

to withstand 150 mph winds through Finite Element Analysis utilizing CFD results.

 

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Greenheck Fan manual High Wind and Hurricane G and GB