6.2 Fans
225
Fig. 6.25 Effect of
increased rotation speed on
the airflow rate and power of
a fan. Modified from
Jorgensen (1999) and
Hensaw et al. (1999)
Airflow rate
Power
Pressure
n 1
Pw 1
Pw 2
Pw 3
n 2
n 3
n 3 > n 2 > n 1
Fig. 6.26 Effect of the
throttling of a fan with a
discharge damper. Modified
from Jorgensen (1999) and
Hensaw et al. (1999)
Airflow rate
Power
Pressure
Power
requirement
reduces
Mored closed