b
System Effect |
|
| |
|
| & | actual system resistance curve |
|
|
| design system |
pressure | system effect |
| resistance curve |
pressure loss | % |
| |
|
| $ | |
|
|
| |
static |
|
| desired |
|
| airflow | |
|
|
| |
|
| airflow | g MO |
x
K
u—
rp” qt p
x”
If unaccounted for during fan selection, the fan – system operating point will fall at f instead of e, delivering a lower airflow than desired.
System Effect
uniform velocity profile
g NC
System effects related to the fan inlet or outlet generally occur when the air is not allowed to establish a uniform velocity profile. If there is not enough straight duct at its inlet or outlet, the fan will not be able to generate the static pressure for which it was rated. If a diffuser that connects the fan to the duct system, an elbow, a branch, turning vanes, or a damper is located too close to
caQ3caM6793O[ | ;; |
