HomeMy WebLinkAboutCertification Of Engineered Flood OpeningsCERTIFICATION OF �A-UINEERED FLOOD OPENINGS (FENi ►'i'8-1 August 2008)
I do hereby certify that the FLOOD SOLUTIONS LLC Flood Vent properly installed and sized in accordance with Federal Emergency Management
Agency's (FEMA's) National Flood Program regulations is designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for entry and
exit of floodwater during floods up to and including the base 100-year flood.
I also do hereby certify that I calculated the Non Engineered Net Free Air and Engineered Opening size for each model and size of FLOOD SOLUTIONS LLC flood
vents. The results of the calculations are recorded in the table below. The Engineered size opening calculation was performed using the formula In FEMA
Technical Bulletin 1— August 2008, Openings in Foundation Walls for Buildings Located in Special Flood Hazard Areas in accordance with the National Flood
Insurance Program (NFIP) and ASCE/SEI 24-05, Flood Resistance Design and Construction.
I measured the Non Engineered Net Free Air by calculating the minimum distance between the top blade and the top of the vent times the clear opening width
of the vent; plus the minimum distance between the bottom blade and the bottom of the vent the clear opening width of the vent; plus the minimum distance
between each blade times the number of spaces between the blades in vent times the clear opening width of the vent.
I used the formula in TB 1— August 2008 (A° = 0,033 [1/C] RAO) to determine the Engineered Opening size for each model listed below. I used the following
assumptions: A° = total net area of openings required (in); 0.033 = coefficient corresponding to a factor of safety of 5.0 (in' hr/ft3); c = 0.40 opening
coefficient (ASCE 24 Table 2-3 "rectangular, long axis horizontal, short axis vertical unobstructed during design flood") or C = 0.35 (square unobstructed during
design flood); R = 5 ft/hr worst case rate of rise and fall; and A@ =1 ft2 total enclosed area.
Note: When the horizontal dimension is twice or more the vertical dimension, use 0.4; as the dimensions approach a square, interpolate from 0,4 to 0.35.
Ao / Ad = 0.033 [1/C] R = 0.033 (1/0.40 for rectangle, long axis horizontal] = 0.4125 in' per ft,
or AO / Ad = 0.033 [1/C] R = 0.033 [1 / 0.35 for square] = .4719 in per ft2
Each individual opening, and any louvers, screens, or other covers, shall be designed to allow automatic entry and exit of floodwaters during design flood or
lesser flood conditions; there shall be a minimum of two openings on different sides of each enclosed area; if a structure has more than one enclosed area
below the DFE, each area shall have openings; openings shall not be less than 3 inches In any direction in the plane of the wall; the bottom of each required
opening shall be no more than 1 ft. above the adjacent grade, the difference between the exterior and interior floodwater levels shall not exceed 1 ft. during
base flood conditions; in the absence of reliable data on the rates of rise and fall, assume a rate of rise and fall of 5ft/hr; where data or analysis indicated more
rapid rates of rise and fall, the total net area of the required openings shall be Increased to account for the higher rates of rise and fall.
MODEL Number
Flood Solutions:
SIZE of OPENING:
(WIDTH X HEIGHT)
Net Free Air
(square inches):
ENGINEERED
OPENING
Each vent covers:
(square ft.)
1412-F
14-1/2" x 12"
67
145
1509-F
16"x 9-1/2"
55
131
1608-F
16"x 8"
51
124
1608-D
16" x 8"
51
124
1608-C
16" x 8"
65
158
1616-F
16"x 16"
104
221
1616-D
16"x 16"
102
216
2412-F
2481x 12"
113
274
2412-D
24"x 12"
110
267
2416-F
24" x 16"
156
362
2416-D
24" x 16"
1S4
357
3208-F
32" x 8"
104
252
3208-D
32" x 8"
104
252
RECEIVEU
APR 0 2 2015
PERM171'1NG
St. Lucie County, FL
SIGNATURE: FA it
NAME: DANIEL G. FARABAUGH ��� ��••'�G E Nd ••®'��e�`�i�
TYPE OF LICENSE: PROFESSIONAL ENGINEER O; No 48849 •�_
*; •�N.
STATE: FLORIDA LICENSE NUMBER: 48349--Rm IL
STATE OF
COPY
DAN FARABAUGH, P.E. E
�. •• �j P •�
FARABAUGH ENGINEERING AND TESTING, INC. �*''• R � '� of
401 WIDE DR., McKEESPORT, PA 15135 01 ••���
PHONE: 412-751-4001 FAX:412-751-4003