ASHRAE Journal - ACMA Supplement - Fall 2013 - 15

130

120

140
150

115
115

150

Note: For both figures, values are nominal design 3-sec. gust wind speeds in
miles per hour (m/s) at 33 ft (10 m) above ground for Exposure C category.

130
120

140

140

150
140
160
150

Figure 3 –
2010 Florida Building 160
170
Code Hurricane-Prone
Region (Simplified. Please

115(51)
120(54)

170

110(49)

130(58)
140(63)

115(51)

180
180

refer to the Florida Building
Code for use on projects).

140(63)
150(67)

150(67)
140(63) 130(58)
120(54)
110(49)
115(51)

160(72)

170(76)

115(51)

150(67)
120(54)
140(63)
130(58)

110(49)
120(54)
130(58)
140(63)
160(72)

140(63)
150(67)
160(72)
170(76)
180(80)
180(80)

150(67)

150(67)

160(72)
170(76)
Puerto Rico

160(72)

Figure 4 – 2012 International Building Code Hurricane Prone Region.
(Simplified. Please refer to the IBC for use on projects)

About High-Wind, High-Rain Louvers
Louvers that pass the AMCA 550 test must have excellent
water management features. Most louvers that pass AMCA
550 will have vertical blades or vertical blades in combination
with horizontal blades. Vertical bladed louvers manage water
much better than louvers with horizontal blades, as they
provide the most direct path for water to travel to the sill pan.
Because architects prefer the aesthetics of horizontal blades,

The 2010 Florida Mechanical Code states:
“401.5 Intake opening protection . . . Louvers that protect
air intake openings in structures located in hurricane-prone
regions, as defined in the Florida Building Code, Building,
shall comply with AMCA 550.”
Both codes define the hurricane-prone regions as the “U.S.
Atlantic Ocean and Gulf of Mexico coasts where the basic
wind speed for Risk Category II buildings is greater than 115
mph (40m/s) and Hawaii, Puerto Rico, Guam, Virgin Islands
and American Samoa.” Figures 3 and 4 highlight the areas
outlined above. Note that all of Florida is considered
hurricane-prone.
15

Fa l l 2 0 1 3

some manufacturers place a horizontal blade louver in front
of a vertical blade louver in a common assembly to meet the
AMCA 550 requirements. In addition to the blade configuration, special sill flashing at the bottom of the louver may be
required. This sill flashing will require end dams and is deeper
than on traditional louvers. These special features help prevent
the large volume of water applied to the louver from passing
under the louver and entering the building.

ConClusion

To provide the code required protection for intake openings,
louvers located in the hurricane-prone regions designated in the
International Mechanical Code and Florida Mechanical Code
must now pass tests in accordance with AMCA 550 Test Method
for High Velocity Wind Driven Rain Resistant Louvers. AMCA
550 subjects louvers to simulated wind levels and rainfall amounts
that simulate hurricane events. Louvers tested to the AMCA
500L water penetration and wind driven rain tests are not subjected to these wind and rain levels and are do not provide
adequate opening protection. Architects and engineers should
review their project locations and code requirements to ensure
that their project specifications require louvers that have been
tested to AMCA Standard 550.

a m c a I n t e r nat I o na l

inmotion

w w w. a m c a . o r g
http://WWW.AMCA.ORG
ASHRAE Journal - ACMA Supplement - Fall 2013

Table of Contents for the Digital Edition of ASHRAE Journal - ACMA Supplement - Fall 2013
