AMCA InMotion - September 2019 - 32

test deﬁned in ANSI/AMCA Standard 500-L, which tells only
the point at which water will be drawn behind a louver.)
The standard allows ﬁxed-blade (open) louvers, operableblade louvers, and combination louver/operable dampers.
Any operable-blade product tested in the closed position
must be clearly identiﬁed as such in product test reports,
product submittals, and installation instructions.

ANSI/AMCA Standard 540
ANSI/AMCA Standard 540 establishes uniform methods for
A louver undergoes an ANSI/AMCA Standard 540
test.

testing a louver's resistance to large missiles as described

ultimate design wind speed is 130 mph (58 m/s) or greater

of Exterior Windows, Curtain Walls, Doors, and Impact

or (b) where the ultimate design wind speed is 140 mph

Protective Systems Impacted by Windborne Debris in

(63.6 m/s) or greater.

Hurricanes, and ASTM E1886-05, Standard Test Method for

in ASTM E1996-04, Standard Speciﬁcation for Performance

Performance of Exterior Windows, Curtain Walls, Doors, and

ANSI/AMCA Standard 550

Impact Protective Systems Impacted by Missile(s) and Exposed

ANSI/AMCA Standard 550 establishes uniform test methods

to Cyclic Pressure Differentials.

and minimum performance ratings for the water-rejection

In an ANSI/AMCA Standard 540 test, a 9-lb (4,100 g)

capabilities of louvers intended for use in high-velocity

2-in.-by-4-in. piece of lumber is ﬁred at a louver specimen

winds, including hurricane-like conditions.

at a rate of 50 fps (15.25 m/s) in an evaluation of Missile

In the performance of an ANSI/AMCA Standard 550

Level D (basic) protection, which most Risk Category I, II,

test, a fan positioned in front of a louver test specimen

and III facilities call for, and at a rate of 80 fps (24.38 m/s)

simulates wind speeds of 35, 70, 90, and 110 mph (15.6,

in an evaluation of Missile Level E (enhanced) protection,

31.3, 40.2, and 49.2 m/s), while water nozzles positioned

which Risk Category IV facilities require.

between the fan and louver test specimen simulate hori-

ANSI/AMCA Standard 540 requires that a test spec-

zontal driving rain at a rate of 8.8 in. (223.5 mm) per hour.

imen be impacted in three speciﬁc locations, including

Each test is performed for 15 min, with the exception of

blade edge and centerline. If a multi-wide or multi-high

the 110-mph (49.2 m/s) test, which is performed for 5 min.

assembly is being considered, any vertical or horizontal

Unlike ANSI/AMCA Standard 500-L water-penetration

mullion conditions also must be impacted.

and wind-driven-rain tests, ANSI/AMCA Standard 550 tests

Like the ANSI/AMCA Standard 550 test, the ANSI/AMCA

do not simulate air being pulled through louvers from

Standard 540 test is pass/fail. Failure occurs if the missile

behind. However, any louver tested to ANSI/AMCA Stan-

penetrates the innermost plane of the louver test specimen

dard 550 must have undergone the ANSI/AMCA Standard

and any adjacent components lose fastener/weld connec-

500-L wind-driven-rain test.

tion or if the missile leaves an opening through which a

The ANSI/AMCA Standard 550 test is pass/fail. Failure

3-in.- (76 mm) diameter solid sphere could pass.

occurs when more than 1 percent of the total volume of
water sprayed penetrates the louver. (It is important to note

Specifying Louvers in Hurricane-Prone Regions

that this can be considered a substantial amount, as much as

Since 2012, the International Mechanical Code has been

2-plus gal. (7.5-plus l), depending on the louver. A distinction

requiring louvers in hurricane-prone regions to be ANSI/

should be made between this test and the water-penetration

AMCA Standard 550-compliant, while the IBC has been

20 19 A M CA i n m o t i o n

w w w. a m c a .o r g

http://www.amca.org

AMCA InMotion - September 2019

Table of Contents for the Digital Edition of AMCA InMotion - September 2019