Locate the static pressure sensor in the correct position to ensure that you can control the bypass damper properly. Figure 1 shows the correct sensor location.
In addition, you must locate the duct static pressure probe in an area where supply plenum pressure is stable. Follow these guidelines when locating the probe:
- Locate the probe at least 10 ft (3.05 m) downstream from the Air Handling Unit (AHU).
- Locate the probe at least 5 ft (1.52 m) downstream from the first turn off of the supply plenum trunk.
- Avoid locating the probe excessively far from the supply plenum trunk or past multiple zone taps.
For a supply plenum tee, locate two probes at least 5 ft (3.05 m) downstream from the main supply trunk on opposing supply plenum branches. Connect the probes with a tee fitting to average the duct static pressure readings from the two supply plenum branches, as shown in the following figure.
| Air Velocity through Damper (FPM) | Damper Size, in. (Area - sq. ft) | |||||
|---|---|---|---|---|---|---|
| 6 (0.188) | 8 (0.338) | 10 (0.532) | 12 (0.769) | 14 (1.050) | 16 (1.375) | |
| Airflow (cfm) | ||||||
|
1500 FPM - Bypass only |
282 |
507 |
798 |
1,154 |
1,575 |
2,062 |
|
1750 FPM - Bypass only |
329 |
592 |
931 |
1,346 |
1,838 |
2,405 |
|
2000 FPM - Bypass only |
376 |
676 |
1,064 |
1,538 |
2,100 |
2,749 |
|
2250 FPM - Bypass only |
423 |
761 |
1,197 |
1,730 |
2,363 |
3,094 |
| Air Velocity through Damper (FPM) | Damper Size, W x H in. (Area - sq. ft) | |||
|---|---|---|---|---|
| 14 x 12 (0.83) | 16 x 16 (1.36) | 20 x 20 (2.25) | 30 x 30 (5.44) | |
| Airflow (cfm) | ||||
|
1500 FPM - Bypass only |
1,245 |
2,040 |
3,375 |
8,160 |
|
1750 FPM - Bypass only |
1,453 |
2,380 |
3,938 |
9,520 |
|
2000 FPM - Bypass only |
1,660 |
2,720 |
4,500 |
10,880 |
|
2250 FPM - Bypass only |
1,868 |
3,060 |
5,063 |
12,240 |