18
APPENDIX B — FAN CURVES
The Vertical Air Handling Unit is equipped with a constant cfm motor which automatically adjusts the fan speed if the actual cfm is
/- 10% of the setpoint cfm.
Figures A-G show fan characteristics at high-speed, medium-speed, and low-speed.
External static pressure on the vertical air handling unit cannot exceed 0.8 in. wg.
0.00
0.20
0.40
0.60
0.80
1.00
EXTERNAL STATIC PRESSURE (in. wg)
H-speed
M-speed
500
AIRFLOW (cfm)
L-speed
700
300 400
600
Upper Limit of ESP
Fig. B — 40VMV018 Fan Curves
Fig. A — 40VMV012 Fan Curves
0.00
0.20
0.40
0.60
0.80
1.00
EXTERNAL STATIC PRESSURE (in. wg)
H-speed
500
AIRFLOW (cfm)
M-speed
L-speed
700
300
600
400
Upper Limit of ESP
0.00
0.20
0.40
0.60
0.80
1.00
400
500
600
700
800
900
1000
EXTERNAL STATIC PRESSURE (in. wg)
AIRFLOW (cfm)
H-speed
M-speed
L-speed
Upper Limit of ESP
Fig. C — 40VMV024 Fan Curves
0.00
0.20
0.40
0.60
0.80
1.00
500
600
700
800
900
1000
1100
1200
EXTERNAL STATIC PRESSURE (in. wg)
AIRFLOW (cfm)
H-speed
M-speed
L-speed
Upper Limit of ESP
Fig. D — 40VMV030 Fan Curves
