I have a model with several VAV systems and have been working on setting them up so the ventilation (outdoor air) is done via the ASHRAE 62.1 ventilation rate procedure. I am comparing the results from the Standard 62.1 Summary report created by EnergyPlus and comparing them to a manual calculation.
My manual calculation is identical to system ventilation requirement for heating, I have however noticed some differences for the cooling.
My manual calculation gives the following average outdoor air fractions (Xs) for cooling:
- VAV_1: 0.107
- VAV_2: 0.090
- VAV_3: 0.091
- VAV_5: 0.490
Here's a snippet of the report generated by EnergyPlus:
ASHRAE 62.1, definees Xs as $Xs =\frac{Vou}{Vps}$
For the cooling report, Xs doesn't seem to be calculated according to the previous formula for VAV_1, VAV_3 and VAV_5 but is for VAV_2. How can that be?
