Louvers against the Elements
– A winnable fight!
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.
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
Louvers!
Form and
Function
Beauty and
Performance
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.
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.
Louver Design Considerations
• When designing louvers, consideration
should be given to the following five criteria:
– Airflow
– Rain Defense
– Structural Integrity
– Noise
– Aesthetics
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).
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
Structural Integrity
• 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
Noise
• Sound Transmission Loss
– ASTM E90-99
• Sound Transmission Classification (STC)
– ASTM E413-87
• Free Field Noise Reduction
Aesthetics
• Louver Shape
– Performance difference
• Finish Type
– To match building construction elements
– Flouropolymer and Anodize most common
Who makes sure these
louvers work?
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.
AMCA International
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
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
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
As An Information Source…
• Test Standards
• Applications Guides
• Certification Programs
• General Publications
• Video and CD Programs
• Order at www.amca.org
AMCA International
Seminars and Training Programs…
• Technical Seminars
• Engineering Conferences
• Training Programs
• TECHSPECS
AMCA
Louver Test Methods
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)
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
Standard 500-L Louvers
Free Area
• Measured
Clearance
• Minimum Inside
Blade to Frame
• Minimum Inside
Blade to Blade
Standard 500-L Louvers
Free Area Tables
By Actual FA
or % FA
Standard 500-L Louvers
Pressure Drop
• Two Test
Configurations
• 5.4 Wall Intake
• 5.5 Wall Discharge
Standard 500-L Louvers
5.4 Wall Intake
Pressure Required to Accelerate Air and Overcome
Losses due to Blockage and Entrance Conditions
Standard 500-L Louvers
5.5 Wall Discharge
Pressure Required to Accelerate Air and Overcome
Losses due to Blockage and Exit Conditions
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
Standard 500-L Louvers
5.6 Water Penetration
Air Exhaust
Waterdrop Manifold
Wetted Wall Manifold
Test Unit
Air Entrained
into chamber
through louver
Exhaust
Fan
Air Flow
Measurement
Collection
Zone
Water
Droplets
“Still Air”
Condition!
Standard 500-L Louvers
• 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
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…
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”
AMCA 5.6 Test Method Water Penetration
Why Traditional Louvers
Don’t Always Stop Rain
Entry
Severe Storm footage - real life conditions.
Extensive, continuous wind-driven rain.
Hurricane/Tropical Storm Floyd
Typical Drainable Louver Shape
“Still Air” Louver in
Wind Driven Rain Test
High Tech Secondary Rain
Defense System
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.
Louver Rain Defense
• Prevents Damage
– Generators,
Production Plants
– Electrical switchgear
areas
• Protects interior finishes
& contents.
– Exhibition Halls,
Warehousing,
Museums…
RAIN
WIND
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.
Standard 500-L Louvers
5.11 Water Rejection Wind Driven Rain
Rain Water
Discharge
Nozzles
Air Exhaust
Wind Driven
Rain plus
Air Entrained
Into Chamber
Through Louver
Exhaust Fan
Collection Zone
Test Louver
Wind/Rain
Machine
“Still Air” vs. Wind Driven Rain Tests
Air Exhaust
Test Louver
Chamber
Straightener
Fan
“Still Air” vs. Wind Driven Rain Tests
AMCA
Wind Driven Rain
Test Duration
AMCA
“Still Air”
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
Goal
40" X 40“ or 48” x48”
Establish louver
effectiveness by
varying test conditions
48" X 48"
Establish point of
beginning water
penetration
AMCA 500-L test. Wind Driven Rain testing at
29 mph wind velocity and 3” of rain per hour
Storm
Resistant
Water has a hard time getting
through a Wind Driven Rain
Louver
Standard
Drainable
Water pours right through a
“Still Air” Drainable louver in
a storm
AMCA 500-L test. Wind Driven Rain testing at
29 mph wind velocity and 3” of rain per hour
Inside
Outside
Water is outside
where it belongs
Wind Driven Rain Louver
NO water penetration
Standard 500-L Louvers
•
•
•
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
RAIN ENTERING YOUR BUILDING
30
STANDARD FIXED
Volume of water entering
a 4’ X 4’ louver during a
one-hour period.
DRAINABLE
25
20
10
5
STANDARD FIXED
15
WIND
DRIVEN
DRAINABLE
LITERS OF WATER PER HOUR
Lets Compare!!!
0
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
60-90 mph windspeeds in real life storms.)
Based on Wind Driven
Rain testing at
29 mph wind velocity
(For comparison
purposes only)
28 liters = approx.
6 1/2 gallons
Standard 500-L Louvers
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)
Louver Evolution:
Up to the Test!
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
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
Drainable Louvers
Good airflow
Looks good
Visible mullions
Rain Entry
Improvement
No Wind Driven
Rain
prevention
Double Drain
Flat
High
Performance
Recessed Drain
Hook
Drainable
Horizontal Line Blade Design
• Most common look
• Adequate blade
support required
• Many blade profiles
for visible or nonvisible lines
• Welded or
mechanically
fastened
• 5’ span for
drainable blades
Visible Mullions
Hidden
Mullions
Vertical Line Blade Design
• Becoming more
widely used
• Excellent
mechanical
performance
• Excellent for
Wind Driven
Rain
Wind Driven Rain Louver Designs
• Sophisticated
Blade Profiles
• Closely Spaced
• Vertical and
Horizontal Blades
• Increased Depth
• Better Pressure
Drop in many
cases
76
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.
Questions?
Louvers against the Elements
– Winning the battle!