AMCA Louver Design Practices

1. Louvers against the Elements
– A winnable fight!

2. The Air Movement and Control Association
International (AMCA), has met the standards
and requirements of the Registered
Continuing Education Providers Program.
Credit earned on completion of this program
will be reported to the RCEPP. A certificate of
completion will be issued to each participant.
As such, it does not include content that may
be deemed or construed to be an approval or
endorsement by NCEES or RCEPP.

3. Learning Objectives
• Define the purposes of a louver
• Describe louver types
• List performance parameters for louvers
• Know how to select the proper louver
• Understand louver construction
• Be familiar with louver accessories, finishes and
installation

4. Louvers!

5. Form and
Function

6. Beauty and
Performance

20. Louver Presentation Outline
I. What is a Louver? Definition and terms.
II. AMCA International: The leader in Air
Movement Test Standards.
III. Louver Test methods: New test methods
lead to new AMCA certified products
providing better rain defense.

21. What exactly is a Louver?
An air termination or entry device
composed of
multiple blades which,
when mounted in an opening
permit the flow of air,
but inhibit the ingress of other elements,
for example rain and noise.

22. • When designing louvers, consideration
should be given to the following five criteria:
– Airflow
– Rain Defense
– Structural Integrity
– Noise
– Aesthetics
Louver Design Considerations

23. Airflow
• Airflow/Volume
– The measurement of the rate of airflow
that passes through a louver,(measured
in cfm/m3s)
• Pressure Drop
– The resistance to airflow across an open
louver (stated in inches of water/kpa)
• Free Area Velocity
– Rate of airflow that passes through the
free area of a louver (expressed in
fpm/ms).

24. Rain Defense
• AMCA 500-L
– The louver test standard
• Water Penetration Test
– The velocity at which .01 ounces of water
passed through the louver
• Wind Driven Rain Test
– New test standard with wind pressure
applied to face of louver
• Effectiveness Class
– New classification of louver performance

25. • Windloads:
– American Society of Civil Engineers
(ASCE) formula
– Hidden or Visible supports
– Effective Wind Speed (mph)
– Louver panel size
• Blade Span (Span tables)
• Intermediate bracing
Structural Integrity

26. • Sound Transmission Loss
– ASTM E90-99
• Sound Transmission Classification (STC)
– ASTM E413-87
• Free Field Noise Reduction
Noise

27. • Louver Shape
– Performance difference
• Finish Type
– To match building construction elements
– Flouropolymer and Anodize most common
Aesthetics

28. Who makes sure these
louvers work?

29. AMCA International
AMCA International …
• Is an independent, third-party, performance
verification organization.
• Administers the Certified Ratings Program.
• Has a state of the art testing laboratory.
• Serves as an information source for publications
and test standards.
• Conducts seminars and training programs.
• Is available on the internet at www.amca.org.

30. Certified Ratings Program…
• Provides independent, reliable, third party
verification of manufacturer’s product performance
ratings.
• Supplies performance information for product
comparisons.
• Requires periodic retesting to verify performance
and allows for challenge testing.
• Establishes criteria for informed decisions on
purchasing and specifying air movement and
control products.
AMCA International

31. Licensed Products…
How do you know the product you specified is
licensed by AMCA International?
• Visit AMCA International’s website ― www.amca.org
and click on Licensed Products.
• Check the manufacturer’s catalogs.
• Look for AMCA International’s Certified Ratings Seal on
the product.
• Contact AMCA International’s Certified Ratings
Program Department ― crp@amca.org.
AMCA International

32. Testing Laboratory…
• State of the art equipment.
• Ability to test to many tests standards.
– AMCA International test standards
– Other recognized standards
• Traceable calibrations of equipment.
• Performs contract tests for any interested party.
• Laboratory accreditation body.
AMCA International

33. As An Information Source…
• Test Standards
• Applications Guides
• Certification Programs
• General Publications
• Video and CD Programs
• Order at www.amca.org
AMCA International

34. Seminars and Training Programs…
• Technical Seminars
• Engineering Conferences
• Training Programs
• TECHSPECS
AMCA International

35. AMCA
Louver Test Methods

36. AMCA Standard 500-L
Tests and Certifies the following:
• Free Air Velocity through Louver
• Pressure Drop
• Beginning Point of Water
Penetration
• Water Rejecting Effectiveness
• Discharge Loss
• Leakage (for operable louvers)

37. Standard 500-L Louvers
The AMCA Seal of Approval
• Water Penetration, Air Performance
• Air Leakage
• Air Performance, Wind Driven Rain
• Wind Driven Rain
• Water Penetration,
Air Performance,
Wind Driven Rain

38. Free Area
• Measured
Clearance
• Minimum Inside
Blade to Frame
• Minimum Inside
Blade to Blade
Standard 500-L Louvers

39. By Actual FA
or % FA
Standard 500-L Louvers
Free Area Tables

40. Standard 500-L Louvers
Pressure Drop
• Two Test
Configurations
• 5.4 Wall Intake
• 5.5 Wall Discharge

41. 5.4 Wall Intake
Pressure Required to Accelerate Air and Overcome
Losses due to Blockage and Entrance Conditions
Standard 500-L Louvers

42. 5.5 Wall Discharge
Pressure Required to Accelerate Air and Overcome
Losses due to Blockage and Exit Conditions
Standard 500-L Louvers

43. Standard 500-L Louvers
Water Penetration or Water Rejection
• Two Test Configurations
• 5.6 Water Penetration for “Still Air”
• 5.11 Water Rejection for Wind Driven Rain

44. Air Exhaust
Water
Droplets
Waterdrop Manifold
Wetted Wall Manifold
Test Unit
Air Entrained
into chamber
through louver
Air Flow
Measurement
Collection
Zone
Exhaust
Fan
“Still Air”
Condition!
Standard 500-L Louvers
5.6 Water Penetration

45. • Test Conditions
• 4” per hour rain
• 1250 fpm max free area
velocity (approx 14
mph)
• Weight of water
penetration per ft2 free
area @ free area
velocity
Standard 500-L Louvers

46. MASTERSPEC - EVALUATIONS
8/93
“Water-penetration testing measures the weight
of water in ounces per sq. ft. of louver free
area passing from the louver’s exterior to the
interior at various air intake velocities...
It is important to realize that the test is based on
still air conditions and simulates the effect of
falling rain and rain flowing down the wetted
surface of a building over a louver…

47. MASTERSPEC - EVALUATIONS
8/93
…While this may provide accurate data
for rain conditions with only fan-induced
air-intake velocities,
no test currently exists that provides
data on louver performance during
exposure to wind driven rain”

48. AMCA 5.6 Test Method Water Penetration

49. Why Traditional Louvers
Don’t Always Stop Rain
Entry

50. Severe Storm footage - real life conditions.
Extensive, continuous wind-driven rain.

51. Hurricane/Tropical Storm Floyd

52. Typical Drainable Louver Shape

53. “Still Air” Louver in
Wind Driven Rain Test

54. International Airport:
Electrical service area for
the Monorail system shut down/
immobilized for days due to poor
louver selection
Standard louvers
used where Storm
Resistant could
have been.
High Tech Secondary Rain
Defense System

55. • Prevents Damage
– Generators,
Production Plants
– Electrical switchgear
areas
• Protects interior finishes
& contents.
– Exhibition Halls,
Warehousing,
Museums…
WIND
RAIN
Louver Rain Defense

56. Louver Rain Defense
• AMCA standard 500-L-99
– AMCA revised its standard to include recommendations
for wind driven rain testing of louvers
• Masterspec 2000
– Includes substantial changes to the advice given when
selecting louvers. Wind driven rain resistant louvers
are now recommended for use.
• Products to meet these needs and
recommendations have been developed
and are increasingly specified.

57. Wind/Rain
Machine
Test Louver
Wind Driven
Rain plus
Air Entrained
Into Chamber
Through Louver
Air Exhaust
Exhaust Fan
Collection Zone
Rain Water
Discharge
Nozzles
Standard 500-L Louvers
5.11 Water Rejection Wind Driven Rain

58. “Still Air” vs. Wind Driven Rain Tests
Chamber
Test Louver
Air Exhaust
Fan
Straightener

59. “Still Air” vs. Wind Driven Rain Tests
AMCA AMCA
Wind Driven Rain “Still Air”
Test Duration 30 minutes (minimum) 15 minutes (minimum)
Air Intake (fpm)
Maximum 1250+ 1250
Minimum No No
Wind Driven Rain Yes No
Rain Fall Rate 75mm/hr (3") 4"/hr
or 200mm/hr (8”)
Static Pressure Drop Yes Yes
Free Area Yes Yes
Test Points Numerous 4
Louver Test Size 40" X 40“ or 48” x48” 48" X 48"
Goal Establish louver Establish point of
effectiveness by beginning water
varying test conditions penetration

61. Water pours right through a
“Still Air” Drainable louver in
a storm
Water has a hard time getting
through a Wind Driven Rain
Louver
Storm
Resistant
Standard
Drainable
AMCA 500-L test. Wind Driven Rain testing at
29 mph wind velocity and 3” of rain per hour
Storm
Resistant
Standard
Drainable

62. Wind Driven Rain Louver
NO water penetration
Water is outside
where it belongs
Outside
Inside
AMCA 500-L test. Wind Driven Rain testing at
29 mph wind velocity and 3” of rain per hour

63. • Rejection
Effectiveness
Classes
A 99% to 100%
B 95% to 98.9%
C 94.9% to 80%
D below 80%
• 3” rain/29 mph wind
• 8” rain/50 mph wind
Standard 500-L Louvers

64. Lets Compare!!!
Volume of water entering
a 4’ X 4’ louver during a
one-hour period.
Based on Wind Driven
Rain testing at
29 mph wind velocity
(For comparison
purposes only)
28 liters = approx.
6 1/2 gallons
RAIN ENTERING YOUR BUILDING
30
25
20
15
10
5
0
LITERS
OF
WATER
PER
HOUR
WIND
DRIVEN
DRAINABLE
60-90 mph windspeeds in real life storms.)
STANDARD
FIXED
Liters entering through a 4' x 4' Louver during
a one hour perios. Liters based on Wind Driven
Rain Testing at 29 mph velocity (equal to
DRAINABLE
STANDARD FIXED

65. Actual/Theoretical airflow
• Discharge Loss Classes
– 1 - .4 and above
– 2 - .3 to .399
– 3 - .2 to .299
– 4 - .199 and below
• EXAMPLE: A2 up to 2 m/s
– at least 99% efficient and between .3 & .399 loss
at 394 fpm core velocity (maximum)
Standard 500-L Louvers

66. Louver Evolution:
Up to the Test!

67. Louver Evolution and Expansion
• “Z” or “J” Non-Drainable Blade Louver
– Good airflow; very little rain defense
• “K” Non-Drainable Blade Louver
– Old “stormproof”; average airflow; very little rain defense
• Drainable Louvers
– Good airflow; some rain defense
• Wind Driven Rain “Storm Resistant” Louvers
– Good airflow on vertical blade; moderate airflow on
horizontal blade; stops most wind driven rain
• “Hurricane” Resistant Louvers –
– Florida Code Compliant Louvers
– Moderate airflow; most stringent tests; severe storm
conditions; missile impact resistance

68. Non-Drainable Louvers
“Z or J” and “K”
Good airflow
Looks good
Stop rain entry?
No! Do not use if
water entry is
a concern
Good as a screen
Cross
section

69. Drainable Louvers
Good airflow
Looks good
Visible mullions
Rain Entry
Improvement
No Wind Driven
Rain
prevention

70. Flat
Hook
Drainable
Double Drain
High
Performance
Recessed Drain

71. Horizontal Line Blade Design
• Most common look
• Adequate blade
support required
• Many blade profiles
for visible or non-
visible lines
• Welded or
mechanically
fastened
• 5’ span for
drainable blades

72. Visible Mullions
Hidden
Mullions

73. Vertical Line Blade Design
• Becoming more
widely used
• Excellent
mechanical
performance
• Excellent for
Wind Driven
Rain

74. Wind Driven Rain Louver Designs
• Sophisticated
Blade Profiles
• Closely Spaced
• Vertical and
Horizontal Blades
• Increased Depth
• Better Pressure
Drop in many
cases
76

75. Louver Presentation Summary
Today we discussed…
I. Louver definitions and terms to familiarize
ourselves with the subject matter.
II. Value of organizations like AMCA International:
The leader in Air Movement Test Standards.
Contact www.amca.org or email amca@amca.org
III. Old and new louver test methods and how louvers
have evolved to keep up with the tests.

76. Questions?

77. Louvers against the Elements
– Winning the battle!