AMCA Standard 500 provides a reasonable basis for testing and rating dampers. Testing to AMCA 500 is performed under a certain set of laboratory conditions. This does not guarantee that other conditions do not occur in the actual environment where dampers must operate.
Designs should provide a reasonable safety factor for damper performance by selecting at some point below damper leakage and pressure drop system requirements.
| Damper Diameter | Maximum System Velocity, cfm (lps) | Leakage with Continuous Seals | Leakage with Sponge Blade-stops | ||
|---|---|---|---|---|---|
| % of Maximum Flow | Total cfm (lps) | % of Maximum Flow | Total cfm (lps) | ||
| 48 in. (1,219 mm) | 2,500 (1,179) | 0.45 | 11.30 (28.7) | 1.40 | 35 (88.9) |
| 36 in. (914 mm) | 2,500 (1,179 | 0.34 | 8.50 (21.6) | 1.10 | 28 (71.1) |
| 24 in. (610 mm) | 2,500 (1,179) | 0.23 | 5.65 (14.4) | 1.00 | 25 (63.5) |
| 12 in. (305 mm) | 4,000 (1,888) | 0.07 | 2.85 (7.24) | 0.40 | 15 (38.1) |
| 6 in. (152 mm) | 4,000 (1,888) | 0.04 | 1.41 (3.58) | 0.20 | 7.5 (19.1) |