AMCA In Motion - Fall 2016 - 26

added in the new version. When developing the sand louver test, the following qualities were considered: * fairness; * repeatability; * performance rating; * comparable testing; * airborne particle size; * mass distribution; and * re-entrainment. The new standard addresses wind-driven sand of particle sizes ranging from 74 microns to 699 microns. It adds a new, self-cleaning prefiltration media for the ventilation industry. The essential test output is sand rejection effectiveness (Es), which is defined by ANSI/ AMCA Standard 500-L as the total mass of sand rejected divided by the total mass of sand injected times 100. Es is reported as a percentage. The airflow pressure drop measurement through the airflow chamber also is reported, and it is certified by AMCA as "air performance." ANSI/AMCA Standard 500-L also defines a new wind-driven sand simulation rig that is capable of producing an airflow rate through the sand louver's free area under test over the range of 1 m/s (197 fpm) to 7 m/s (1,378 fpm). These rates are consistent with the common airflow specifications used by most H VA C d e s i g n e r s f o r i n l e t s t h r o u g h louvers. The test rig (Figures 4 and 5) was constructed by Thomas Bell-Wright Independent Consultants in Dubai, which was subsequently designated as an AMCA independent accredited laboratory after undergoing rigorous certification procedures. Tests are conducted on a louver with outside dimensions of 1220 mm x 1220 mm (48 in. x 48 in.) with a tolerance of +0, -6.3 mm (+0, -0.25 in.). Sample products are required to be as-built, unpainted, cleaned, degreased and without additional factory-applied coating on the product surface. They are tested in the full open position without a screen across the air passages of the louver. The wind-driven sand chamber is equipped with ducted sand injector equipment capable of blowing calibrated sand, in accordance with ISO 14688-1 and ISO 14688-2, at an air velocity of 20-25 m/s (Figure 6). ANSI/ AMCA Standard 500-L requires the test sand to be dry and to have particles size 26 Summer 2016 distributions conforming to Table 1, which closely resembles desert sand. In addition to publishing a sand louver test standard, AMCA amended its certified ratings program, allowing for the certification of sand louver ratings test data and manufacturers' published catalog data. AMCA Publication 5114 outlines the procedures for certifying sand louvers and explains how a product can be licensed to bear the AMCA Certified Ratings Program seal (Figure 7). AMCA Publication 511 defines four classes of sand penetration effectiveness, as shown in Table 2. CONCLUSION Figure 7. AMCA Certified Ratings Program seal for sand louvers. Image courtesy of AMCA International. Grade (µm) Mass (%) >699 0.5 423-699 3.0 353-422 12.0 251-352 30.0 211-250 20.0 152-210 27.0 104-151 6.0 76-103 1.0 <76 0.5 Table 1. Requirements for standard test sand (Table 8 from ANSI/AMCA Standard 500-L). Class Effectiveness A 100% to 90% B 89.9% to 80% C 79.9% to 70% D Below 70% Table 2. AMCA Publication 511 defines four class levels of sand penetration effectiveness. The classifications apply at various free area velocities. AMCA inmotion Increased cleaning frequency, overheating fans, frequent air filter replacements, system downtime to accommodate sand-related service calls - without the prefiltering effect of sand louvers, the costs of maintenance in desert or coastal areas are high. Sand intrusion takes a toll on the market. The new AMCA testing procedure and certification of ratings will help establish a credible foundation for evaluation of these cost-saving pieces of equipment. Architects, engineers and building owners will not only be able to accurately evaluate the benefit of sand louvers; they will also be able to better understand the specific performance requirements for effectiveness for their projects. REFERENCES 1. ASHRAE Standard 52.1. Gravimetric and Dust-Spot Procedures for Testing AirCleaning Devices Used in General Ventilation for Removing Particulate Matter. Atlanta. ASHRAE. 1992. 2. ASHRAE Standard 52.2. Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size. Atlanta. ASHRAE. 2012. 3. ANSI/AMCA Standard 500-L-12 (Rev. 2015). Laboratory Methods of Testing Louvers for Rating. Arlington Heights, Ill. AMCA. 2015. 4. AMCA Publication 511. Certified Ratings Program-Product Rating Manual for Air Control Devices. Arlington Heights, Ill. AMCA. 2015. W W W. A M C A . O R G http://www.amca.org http://WWW.AMCA.ORG

Table of Contents for the Digital Edition of AMCA In Motion - Fall 2016