Auto-Zone Control Systems Auto-Zone Basic Systems Installation & Operation (Version 02C) - Manual (Page 21)

Auto-Zone Basic Section 1
Design Guide 1-15
Round Dampers
Table 1-1: Round Air Damper Selection
Rectangular Dampers
Table 1-2: Rectangular Damper Selection
Round Air Damper Selection
Air Damper Round Duct Size
( Area Ft
2
)
6”
(0.188)
8”
(0.338)
10”
(0.532)
12”
(0.769)
14”
(1.050)
16”
(1.375)
Velocity Through Round Air
Damper
(FPM)
Volume Through Round Air Damper
(CFM)
750 - Zone 141 254 399 577 788 1031
1000 - Zone 188 338 532 769 1050 1375
1250 - Zone 235 423 665 961 1313 1718
1500 - Zone 282 507 798 1154 1575 2062
1750 - Bypass Only 329 592 931 1346 1838 2405
2000 - Bypass Only 376 676 1064 1538 2100 2749
2250 - Bypass Only 423 761 1197 1730 2363 3094
Rectangular Damper Selection
Damper
Height
(B)
8” 10” 12” 14” 16” 18” 20” 22” 24” 26” 28” 30” 32” 34” 36”
Damper
Width
(A)
Airflow Through Rectangular Damper
CFM @ 1000 FPM Velocity
8” 410 530 640 740 850 970 1080 1190 1300 1410 1520 1630 1740 1850 1970
10” 510 590 690 800 910 1030 1150 1260 1380 1500 1610 1730 1840 2000 2080
12” 560 650 730 850 970 1090 1210 1330 1460 1580 1700 1820 1940 2060 2190
14” 660 770 880 1030 1180 1330 1480 1630 1760 1910 2060 2210 2360 2510 2640
16” 750 890 1030 1200 1370 1540 1710 1880 2060 2230 2400 2570 2740 2910 3090
18” 770 980 1180 1380 1580 1780 1980 2180 2350 2550 2750 2950 3150 3350 3540
20” 850 1090 1330 1550 1770 1990 2210 2430 2650 2870 3090 3310 3530 3750 3990
22” 930 1210 1480 1730 1980 2230 2480 2730 2950 3200 3450 3700 3950 4200 4440
24” 950 1290 1630 1900 2170 2440 2710 2980 3250 3520 3790 4060 4330 4600 4880
26” 990 1390 1780 2080 2380 2680 2980 3280 3550 3850 4150 4450 4750 NA NA
28” 1070 1500 1930 2250 2570 2890 3210 3530 3850 4170 4500 4820 NA NA NA
30” 1020 1550 2080 2430 2780 3130 3480 3830 4150 4500 4850 NA NA NA NA
32” 1090 1660 2230 2600 2970 3340 3710 4080 4450 4820 NA NA NA NA NA
34” 1150 1770 2380 2780 3180 3580 3980 4370 4750 NA NA NA NA NA NA
36” 1060 1790 2520 2670 3090 3510 3930 4350 5040 NA NA NA NA NA NA
Notes: 1.) Zone Dampers Should Be Sized Based On The Required Zone CFM. The Table Above Is
Calculated Based On 1000 FPM Velocity Through The Rectangular Damper. Zone Damper
Recommended Velocity Is 1000 – 1500 FPM. Select 1000 FPM or Less for Quiet Operation. For Other
Velocities, Use The Following Multipliers To Obtain The Correct CFM: 500 FPM = 0.5, 750 FPM =
0.75, 1250 FPM = 1.25, 1500 FPM = 1.5, 2000 FPM = 2.0, 2250 FPM = 2.25.
2.) Bypass Dampers Should Be Selected for 60% to 70% of the HVAC Units Rated CFM Capacity.
Recommended Bypass Damper Velocity is 1750 – 2250 FPM.