Louvers against the Elements – A winnable fight!

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 ObjectivesLearning Objectives

• Define the purposes of a louverDefine the purposes of a louver• Describe louver typesDescribe louver types• List performance parameters for louversList performance parameters for louvers• Know how to select the proper louver Know how to select the proper louver • Understand louver constructionUnderstand louver construction• Be familiar with louver accessories, finishes and Be familiar with louver accessories, finishes and

installationinstallation

Louvers!Louvers!

Form and Form and FunctionFunction

Beauty and Beauty and PerformancePerformance

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?What exactly is a Louver?

An air termination or entry device An air termination or entry device composed of composed of

multiple blades which, multiple blades which, when mounted in an openingwhen mounted in an opening

permit the flow of air, permit the flow of air, but inhibit the ingress of other elements, but inhibit the ingress of other elements,

for example rain and noise.for example rain and noise.

• When designing louvers, consideration should be given to the following five criteria:

– Airflow

– Rain Defense

– Structural Integrity

– Noise

– Aesthetics

Louver Design Considerations

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

• 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

• Sound Transmission Loss

– ASTM E90-99

• Sound Transmission Classification (STC)

– ASTM E413-87

• Free Field Noise Reduction

Noise

• Louver Shape

– Performance difference

• Finish Type

– To match building construction elements

– Flouropolymer and Anodize most common

Aesthetics

Who makes sure these louvers work?

AMCA International

AMCA International …

• Is an independent, third-party, performanceverification organization.

• Administers the Certified Ratings Program.

• Has a state of the art testing laboratory.

• Serves as an information source for publicationsand test standards.

• Conducts seminars and training programs.

• Is available on the internet at www.amca.org.

http://www.amca.org/

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 ― [email protected].

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 International

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

Free Area

• Measured

Clearance

• Minimum Inside

Blade to Frame

• Minimum Inside

Blade to Blade


By Actual FA or % FA


Free Area Tables


Pressure Drop

• Two Test

Configurations

• 5.4 Wall Intake

• 5.5 Wall Discharge

5.4 Wall Intake

Pressure Required to Accelerate Air and Overcome Losses due to Blockage and Entrance Conditions


5.5 Wall Discharge

Pressure Required to Accelerate Air and Overcome Losses due to Blockage and Exit Conditions



Water Penetration or Water Rejection

• Two Test Configurations

• 5.6 Water Penetration for “Still Air”

• 5.11 Water Rejection for Wind Driven Rain

Air ExhaustWater

Droplets

Waterdrop ManifoldWetted Wall Manifold

Test Unit

Air Entrained into chamber through louver

Air Flow Measurement

Collection Zone

ExhaustFan

“Still Air” Condition!


5.6 Water Penetration

• 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 LouversDon’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

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

• Prevents Damage– Generators,

Production Plants– Electrical switchgear

areas• Protects interior finishes

& contents.– Exhibition Halls,

Warehousing, Museums…

WINDWIND

RAINLouver Rain Defense

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.

Wind/RainMachine

Test Louver

Wind DrivenRain plus

Air EntrainedInto Chamber

Through Louver

Air Exhaust

Exhaust FanCollection Zone

Rain WaterDischargeNozzles


5.11 Water Rejection Wind Driven Rain

“Still Air” vs. Wind Driven Rain Tests

Chamber

Test LouverAir Exhaust

Fan

Straightener

“Still Air” vs. Wind Driven Rain TestsAMCA 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

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

Wind Driven Rain LouverNO water penetration

Water is outside where it belongs

OutsideInside

AMCA 500-L test. Wind Driven Rain testing at 29 mph wind velocity and 3” of rain per hour

• 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


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

LIT

ERS

OF W

ATER P

ER H

OU

R

WIND DRIVEN

D

RAIN

ABLE

60-90 mph windspeeds in real life storms.)

S

TAN

DARD

FIX

ED

Liters entering through a 4' x 4' Louver duringa one hour perios. Liters based on Wind Driven Rain Testing at 29 mph velocity (equal to

DRAINABLE

STANDARD FIXED

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 airflowLooks goodStop rain entry?

No! Do not use if water entry is a concern

Good as a screen

Cross section

Drainable LouversGood airflowLooks goodVisible mullions

Rain EntryImprovement

No Wind Driven Rainprevention

FlatFlat

HookHook

DrainableDrainable

Double DrainDouble Drain

High Performance

High Performance

Recessed DrainRecessed Drain

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

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 [email protected]

III. Old and new louver test methods and how louvers have evolved to keep up with the tests.


Questions?Questions?

Louvers against the Elements – Winning the battle!

Documents

Louvers against the Elements – A winnable fight!