The Air Movement and Control Association (AMCA) recently introduced AMCA Standard 540 that
requires Large Missile Impact testing for louver products. The new AMCA Standard subsequently
has been adopted by the 2012 International Building Code (I B C), in accordance with
the American Society of Civil Engineers (A S C E) version 7-10, for certain types of
buildings and structures located within the Wind-Borne Debris Region of the Hurricane
Prone Region.
The Hurricane Prone Region is any location along the Gulf of Mexico Coast and the Atlantic
Coast where the basic wind-speed is greater than 105 miles per hour for Risk Category
1 buildings, 115 miles per hour for Risk Category II buildings or 120 miles per hour for Risk
Category III or IV buildings. We will explain what types of buildings are in those risk
categories later in this video. Other areas considered within the Hurricane Prone Region
include Hawaii, Guam, Puerto Rico, American Samoa and the Virgin Islands. The Wind-Borne
Debris region is any location within the Hurricane Prone Region where the basic wind-speed is
140 miles per hour or 130 miles per hour if within 1 mile of the coast for Risk Category
II, III or IV buildings.
It is critical that design professionals fully understand what these new standards require
when specifying and selecting Louver products for the Hurricane Prone Region. The new AMCA
540 standard for Large Missile Impact is very similar to A S T M E 1996 or what Florida
refers to as T A S 201. The most significant difference is that the AMCA 540 standard now
requires that louvers be tested at 2 different missile speeds by the manufacturer depending
on the type of building and its location within the Hurricane Region. Missile level "D" is
a 9 lb. 2 x 4 traveling at 34 miles per hour. Missile level "E" is a 9 lb. 2 x 4 traveling
at 55 miles per hour. Determining which one of these tests your louver products may need
to conform to, if any, depends entirely on the type of building or structure and where
it's located within the Hurricane Prone Region.
This map created by Greenheck shows the approximate location of the Hurricane Prone Region in
the southeastern U.S. Risk category I buildings are defined as having low risk to human life
in the event of failure. Examples might be barns, pump houses, and grain silos. The 2012
International Building Code does not reference Risk Category I buildings as requiring Large
Missile Impact testing.
Risk category II buildings are defined as those buildings not otherwise defined in Risk
Category I, III or IV and may include office buildings, hotels and restaurants, for example.
The 2012 International Building Code requires that ventilating louvers in Risk Category
II Buildings in these areas and located within 30 feet of grade must meet the requirements
of AMCA 540. It is reasonably safe to assume these louvers would at a minimum need to comply
with the AMCA 540 missile level "D" requirement.
Risk Category III buildings are those that may have substantial economic impact or mass
disruption of day-to-day civilian life in the event of failure, or those that are not
included in Risk Category IV that may contain toxic or explosive substances that pose a
threat to the public. Risk Category IV buildings are considered
Essential Facilities, where failure would cause substantial hazard to the community,
buildings containing toxic or explosive substances considered a threat to the public, or buildings
required to maintain the functionality of other Risk Category IV structures. Examples
may include hospitals, essential response facilities, schools and stadiums.
The 2012 International Building Code requires that ventilating in Category III and IV buildings,
and located within 30 feet of grade, shall meet the requirements of AMCA 540 if located
within the Wind-Borne Debris region. Some Risk Category III or IV buildings or structures
may only require AMCA 540 missile level "D". However, it is reasonably safe to assume that
most Risk Category III or IV buildings or structures and all Essential Facilities will
require AMCA 540 missile level "E" requirements. Design professional s should consult with
local building code officials to determine which level of missile testing is required
for these types of buildings.
Rest assured that Greenheck is prepared for the new standards established within the 2012
International Building Code relative to our large missile impact qualified louver products.
All Greenheck Florida Building Code County approved and Miami-Dade Qualified louvers
have been subjected to, and have passed, not only the AMCA 540 missile level "D" standard,
but also the accelerated missile level "E" standard required for all Essential Facilities.
For more information on Greenheck's industry leading line of performance louver products,
contact your local Greenheck representative or visit us at www.greenheck.com.