AMCA 500-L has two very different procedures relative to weather simulation for louver
products.
The AMCA 500-L test for Water Penetration simulates rain falling straight down in front
of a louver at a rate of 4 inches per hour with a fan behind attempting to pull the water
through the louver.
The free area velocity up to 1250 feet per minute where only 0.01 ounces of water per
square foot of louver free area is measurable is considered the Beginning Point of Water
Penetration.
Conventional louvers like the Greenheck ESJ or ESK series typically have a Beginning Point
of Water Penetration around 700 feet per minute free area intake velocity.
Conventional drainable blade louvers like the Greenheck ESD series typically have velocities
at Beginning Point of Water Penetration in excess of 1000 feet per minute free area intake
velocity.
Conventional non-drainable or drainable blade louvers perform well in most applications,
however; they lend very little defense against wind-driven rain.
For this reason it is critical that building designers ensure provisions to manage water
penetration even if the louvers are sized well below the velocity at the Beginning Point
of Water Penetration.
When provisions to manage weather are more limited Greenheck recommends the application
of wind-driven rain style louvers such as our EHH or EVH series.
The AMCA 500-L test for Wind-Driven rain is considerably more dynamic.
The Wind-Driven Rain test simulates external wind speeds of 29 or 50 MPH while spraying
water directly at the face of the louver at a rate of 3 or 8 inches per hour.
3 inches occurs at 29 MPH and 8 inches occurs at 50 MPH.
Behind the louver is a fan attempting to pull the wind-driven rain through the louver.
At specific escalating inlet velocity points the product is judged with a letter grade
rating of A, B, C or D. Class A is defined as 99% effectiveness or greater.
Class D is defined as less than 80% effective.
Horizontal blade wind-driven rain louvers like the Greenheck EHH-601 provide excellent
defense against wind-driven rain.
Greenheck EHH-601 maintains Class A wind-driven rain performance up to 1391 feet per minute
free area intake velocity during the 29 mile per hour 3 inch rain per hour test.
During the 50 mile per hour 8 inch rain per hour test EHH-601 maintains Class A wind-driven
rain performance up to 1232 feet per minute free area intake velocity.
For maximum defense against wind-driven rain, Greenheck recommends vertical blade louvers
like the Greenheck EVH-602.
Greenheck EVH-602 maintains Class A wind-driven rain performance up to 2030 feet per minute
free area intake velocity during both the 29 mile per hour 3 inch rain per hour test
and the 50 mile per hour 8 inch rain per hour test.
For more information about the AMCA 500-L tests for Water Penetration and Wind-Driven
Rain or Greenhecks' industry leading line of performance louver products please consult
your local Greenheck representative or visit us at www.greenheck.com.