AMCA 540 vs 550: Comparing Louver Standards

When it comes to measuring the efficiency of louvers, there are a couple of tests and standards that top-notch louvers are measured by. These tests use hurricane-force winds and water penetration to ensure that any louver that meets them will be able to withstand the challenges that any storm brings their way. 

AMCA 540 and AMCA 550 are the two main types of tests used to measure the efficacy of louvers when faced with extreme storm conditions. In order to provide an assessment of what you can expect from louvers that meet these standards, let’s take a look at what the tests entail, as well as what type of louvers are the best when it comes to resisting storm damage.

Test Conditions

Both of these tests use extreme conditions to simulate the real world effects of wind-driven rain and wind-flown debris on louvers. An isolated test area is set up with a louver built into a frame. The louvers are then subjected to wind-driven rain and flying debris that simulates what they might expect to face in a hurricane. There is a strictly enforced pass/fail scenario which ensures that no louver can meet the standards unless it adheres to the level of resistance required.

AMCA 540 Louver Codes

The AMCA 540 test is used to measure flying debris resistance specifically. A louver is mounted into a test assembly where a cannon then fires a piece of 2 x 4 lumber directly at it. The louver will be struck in multiple key places across its face including spots where the louver blades connect to the frame. This action is meant to simulate what the louver could expect to face during hurricane force winds.

In order for the louver to pass this test, each blade must remain firmly affixed to the frame while the frame itself must remain intact. If the frame is bent out of shape or if any blade comes loose from the frame, the louver will fail the AMCA 540 test. 

AMCA 540 has the strictest standards of any windborne debris test for louvers. A louver must present four versions of itself, one size to maximum height and width, one size to maximum height, one size to maximum width, and a multi-panel assembly where each louver is sized to maximum width. 

The distance between the cannon and the louver must be exactly 1.5 times the length of the projectile as well, a stricter standard than other tests for windborne debris, like the TAS 201 test, for example. Multiple different codes such as the IBC and the FBC have adopted this standard, with their standard being the highest because of the the level of windborne debris and high winds they regularly face as a result of recurrent hurricanes. 

AMC 550 Louver Code

The AMCA 550 test is meant to measure water penetration at hurricane speeds. A sample louver is mounted into a test assembly  with a collection chamber inside the opening of the louver. This chamber has an open top and has walls lined with plastic to allow the water to easily slide down into a collection bucket at the bottom. The bucket is metered and will show exactly how many milliliters of water have been allowed to pass through. 

How does the AMCA 550 test work?

When the test starts, water will be injected into an airstream directed at the louver. The test will start at a speed of 35mph, then up to 70mph, then 90mph, and finally 90mph. The stream will remain constant throughout the test in order to simulate a total of 8.8 inches of rainfall per hour. For each interval, the wind and rain will continue for 20 minutes and pause for 10 minutes to allow airflow, with each interval being 30 minutes in total.  

At the end of each test interval, the metered bucket will be checked and in order for the louver to pass the AMCA 550 test, the level of water inside the bucket must not exceed 1% of the total amount of water applied during the test. This means the louver must block 99% of the water it faces during each test interval and if any one interval fails, the louvers will fail the test completely. This makes AMCA 550 the strict wind-driven rain test for louvers.

The Best Louvers for AMCA Standards

Aire Renaissance by OSA louvers meet the strictest louvers standards while also being drainable, meaning they drain all water through internal gutters as opposed to letting it drip off the face and cause a cascading water-fall effect that many find unsightly. 

Most of their products are drainable, and even their basic louvers meet AMCA 500-L standards for wind-driven rain, which often coincides with  AMCA 540 and 550 standards. If you want the best in louver technology when it comes to storm-resistance, don’t hesitate to get in touch with Aire Renaissance by OSA today.