Hi everyone, I have this project where the HVAC engineer is designing some interesting HVAC system based on load profiles.

The intent of this strategy is to have one HVAC system running at somewhat 80% of its capacity almost all year around, but when peak load exceeds the main system capacity (this is anticipated to happen no more than 25% of the year), the second HVAC system enters as a backup system. Main system is air handling units connected to absorption chiller, backup is connected to air cooled chillers.

Another system designed for another zone is as follows: DOAS pre-cooling outside air and supplying it to Fan and Coil units. So the F&C could be downsized to just beating the room internal gains.

Has anyone have experienced systems as complicated as these ones and how could I ideally model them in any software? Since most softwares limit one system per thermal zone.