I'm working on FCU + DOAS system, I find that if I increase the outdoor air Volume., the load of FCU coil and DOAS coil will increase simultaneous (component sizing summary). the load has been doubled.
what shall I do if I want to use FCU deal with internal load, while use DOAS to deal with outdoor air load.
thank you
Set the outdoor air flow rate in your fan coil units to zero and then add a DOAS air loop with terminals serving each zone.
ok, I have a DOAS terminal (AirTerminal:SingleDuct:VAV:NoReheat), but how can I set OA to this terminal? I find no OA setting in this air terminal.
Set the outdoor air requirement with the DesignSpecificationOutdoorAir object. Alternatively, you can use the AirTerminal:SingleDuct:Uncontrolled object and size the terminal for the outdoor air flow rate directly. Make sure the sizing criteria for the air flow is set to account for the DOAS and sized to air flow requirement.
Comments
Do you have an outdoor air flow rate set in your fan coil units?
yes, I add the OA flow rate in the HVACTemplate:Zone:FanCoil,, because I'm not sure how to add OA flow rate directly into the HVACTemplate:System:DedicatedOutdoorAir,.