[Equest-users] 100% outdoor air system

[Maria Ramos]

All, I am modeling a large research tower, 470,000 SF.  On past projects, all of the HVAC systems were 100% outdoor air with heat pipe energy recovery.  On this project, we will be returning part of the building, yielding 81% outdoor air.  I am trying to model the energy savings.  Equest is actually showing an increase in utility costs for going from 100% to 81%, both with and without energy recovery, which is the opposite of what I expected.  Both versions of the baseline have economizer.  If I compare the utility consumption, it looks as if the fan energy has increased significantly by decreasing the amount of outdoor air (entered as a fraction on the system outdoor air tab) and the cooling energy has increased a little.
 
Does anyone have any idea what combination of inputs that I have that would lead to this problem?  It seems to me that these results couln't be valid.
 
Thanks,
Maria Ramos, PE
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