[Equest-users] Difference between fan energy consumption almost same using constant speed and variable speed fan control

[Nitin Harjai]

Hi all,

I am working on the project where the project space is served by chilled
water to meet the building heat load. And in eQuest, I have considered the
single zone Reheat system under the Air Side HVAC tab for AHU having 14200
CFM working 9 hours 6 days a week.

My doubt is that whether I set the fan controls constant speed or variable
speed, the software generated fan energy consumption KWh are nearly the
same (only a  difference of 16 KWh) between both the cases.

This seems that I will not get the benefit of variable speed fan control in
case there is a VFD equipped to AHU.

Can anyone help me why there is a very little difference in fan energy
consumption using constant speed and variable speed fan in the model.
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