I am after a bit of help, we are unsure as to when we use Fresh Air Loads or Fixed Temperature Air in the CIBSE heatgain programme. We are currently working on a project where we have a central AHU with a heater battery only and rooms which will be cooled by Fan Coil Units. The Fan Coil Units need to be sized to do both the fabric gain and the air load if the outside temp is a maximum of 30 degrees and the room needs to be controlled at 24 degrees. Which boxes do we use in Design Data?

Thank you