I am modeling a lab building with zonal exhaust from fume hoods that one of
our intended modifications is to redo some ductwork to reduce static
pressure losses. I have input the exhaust static pressure and exhaust fan
efficiency in the affected zones and turned on tracking the supply airflow.
This seemed to cover the make-up air requirement at the system level fine,
but when I reduced the exhaust static pressure, it made no difference in the
electrical consumption at all. Can anyone help me with making sure this fan
energy was accounted in the first place and then if there's something else I
need to do to reduce it.

Thanks in advance for any replies.

Rick Routh