The design model has an AHU that supplies air for some zones. During the winter season the AHU humidifies the air through an atomising humidifier. Some other zones are conditioned through hydronic systems (heated floor or radiator) but they are not mechanically ventilated (therefore they aren't humidified).
The baseline model is System 7. How shall I model the humidification in the baseline model? I know that the humidification shall be modeled in the same way in both models (like the process loads), but in this case it isn't easy. I mean, in the baseline model every system is connected with all the conditioned zones of a floor (both the zones that in design model are mechanically ventilated and the zones that aren't mechanically ventilated). If I modeled System 7 with the humidification system, every conditioned zone would be modeled as humidified, also the zones that aren't humidified in the design model. It doesn't seem correct.
Consider that the air, in order to be adequately humidified, is preheated (with an atomising humidifier in the psychrometric chart the humidification process is on a constant enthalpy line). If in the baseline I modeled all the conditioned zones as humidified, I would consider more energy also because more air would be preheated by a heat coil and then cooled by the humidifier.
Shall I consider the humidification as a process load and therefore shall I apply exception b. (G3.1.1) for the zones that aren't humidified in the design?