I'm working on a multi-use building with 3 stories of apartments on top of a story of retail. I'm using a split DX heat pump for each apartment, which I'm simulating in TRACE as PTAC units. I know I can use zone multipliers to group together identical units across multiple floors.

If I use zone multipliers instead of simulating each and every apartment and heat pump, how do I reflect this in the energy model? If I were to create a system for each individual PTAC, I would set the coil capacities to whatever the unit can put out. But I'm confused how TRACE factors in zone multipliers with unit capacities.

For instance, let's say I have 4 identical apartment. Each has a heat pump that puts out 12 Mbh cooling and 9 Mbh heating. In the "Create Systems - Heating and Cooling Coil Overrides" menu, would I put the coil capacities at 12 Mbh and 9 Mbh, with TRACE automatically creating four identically-sized coils? Or would I have to multiply it out myself and put the capacities at 48 Mbh and 36 Mbh, with TRACE splitting the total capacity between the four apartments? Or would I have to do it another way altogether?

Thank you!