I am working on a LEED job comparing a 2FDD system to a VAVRH system
using A90 Appendix G. The humidification load on the 2FDD uses the room
total cfm for sizing where the VAVRH uses the minimum OA for sizing.
200,000 cfm verses 50,000 cfm. The 2FDD humidification load is nearly
four times the VAVRH. Per Trace Help both humidification coils are at
the same location as the cooling coil.

Can anyone offer an explanation.

Thanks

Robert Vogt