I am looking at a simple VAV system and using Ventilation Rate Procedure on it. Below is a snippet from the EnergyPlus output.

The parameter Xs is very clearly defined as Xs = Vou/Vps. In the table below, I would therefore expect the following:

AHU-1 0.187
AHU-2 0.164
AHU-3 0.166
AHU-4 0.183
AHU-5 0.183

Yet, the table shows:

AHU-1 0.181
AHU-2 0.146
AHU-3 0.154
AHU-4 0.183
AHU-5 0.183

Any idea why that is so?