HomeMy WebLinkAboutCERTIFICATION ENGINEERINGS_AWNED
ey
St. 11,ucie CoMY
Certification of Engineered Flood Openings
In accordance with NFIR, FEMA 'I`R 1-08, and ASCE/S-Si- 24-US
I here i y certify that the Crawl Space Door Systems flood vents 816CS,1220CS, 1232CS, 1616CS, 1624CS;1632CS, 2032CS, 2424CS,
and 2i1, 36CS are designed in accordance with the requirements of the NFIP "Fiood.insurance Manual" (2011) to.provide automatic
equalization of hydrostatic flood forces by allowing for the entry and exit of floodwaters, when properly installed and sized as set
forth elow. This certification follows the design requirements and specifications established in FEMA Technical Bulletin 1-08,
"Openings in Foundation Walls and Walls of Enclosures Below Elevated Buildings in Special Flood Hazard Areas", and the ASCE
Standard for "Flood Resistant Design and Construction" (ASCE/SEI 24-05)• The actual vent opening measurements were determined
and �' rtified by Mr. Christopher Mark, Loney, Virginia,PE No. 029000, Calculations are based on thespreaids11pot 1'ormUlas, and
"Rev! w of certification of Engineered Flood Openings, dated January 16, 2012" prepared by Dr., Georg Reichard, Associate Professor -
o(Bu�i ding Construction, Virginia Tech.
Design Characteristics
Sectio� 2.6.2.2 of ASCE 24 provides an equation to determine the required net area of engineered openings (k) for a given enclosed
area''
J. This equation is based on the hydraulic formula for the flow rate across sharp edged orifices. I have utilized this equation
to ca -ulate 1) the respected flow rate through the individual openings between louvers; 2) the flow rate through the main frame
opens g In case'the louver is blown out during a flood event; and 3) the flow rate of water flowing through louver blades following
hydr;alit short tube theory. The ultimate maximum total enclosed area (AJ that can be serviced by a single vent has then been
deter pined by utilizing the lowest flow rate of the three assessed scenarios for each vent and .is listed in Table 1.
These values are based on the following assumpfions:
Iji absence of reliable data, the rates of rise and fail have been
a sumed with 5 feet/hour;
Pe (maximum) difference between the exterior and Interior
fl odwater levels has been assumed with 1 foot during base
food conditions;
9 1 factor of safety of 5 has been assumed, which Is consistent
it ith design -practices related to protection of life and property*
T ie net -area of openings (A J as. provided by the manufacturer.
I�
insi' ilation Requirements and Limitations
*)
Model
HxW
(in]
A,,
[in']
AL.
[ft2J
❑
816CS
8 x 16
106
205
❑
1220CS
12 x 20
237
Soo
El
1232CS
1202 32
306
645
El1616CS
.
16 x 16
184
305
p
1624CS
16 x 24
312
T 610
1632CS
16 x 32
408
835
[]
2032CS
20 x.32
630
1240
❑
2424CS
24 x,24
`570
1230
2436CS
24-x 36
17GS
This (certification will be voided if thefollowing installation
requ � ements and limitations are not enforced:
Table i Maximum total enclosed area (A0) that can be
here -shall be a minimum. of two openings on different sides of served. by each individual model based on the
each enclosed area; given"net area of engineered openings.(A,)
a he bottom of each required opening shall be no more than 1ft
Bove the adjacent ground level;
• Zo temporary (e.g. during cold weather) or permanent solid cover may be placed into or over the flood vent that would block
e automatic entry or exit of floodwaters at any time;
• here analysis indicates rates of rise and fall greater than 5 ft/hr, the total enclosed area as given In Table 1 shall be reduced
ccordinely to account for the higher rates of rise and fall.
Cer; fying,Desggn Professional '41t111:l1
�ame, Title Steve A. Geci, President, Gecl & Associates Engineers, Inc.
it Address 2950 N 1;e' Avenue, -Pensacola, FL - M03
a •
0
License Florida Professional Engineer, Lic se' o. 33fi58 � No. 33859
Signature ±"o ; �a
s ; ST�RTE ®F e•�'w;
idehihificaiion of the BuildingsBQN
. and installed Fl®od Vents (By Others) e
-The �Ilood vent models marked In Table 1*) are being installed at the following bull
Su, Ing Address
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