PSZ serving multi zones (90.1 PRM)

[enerGwizz]

Hi All,

I am a bit of a novice with ApacheHVAC, so I wanted to run something by this forum before jumping too far into it.

My project has fan coil units that each serve multiple rooms of different occupancy types (corridor&restroom, office&conference, etc.). The individual rooms have thermal templates by occupancy type and per 90.1 space-by-space definitions (I am using the PRM Navigator), so I don't want to merge them into one space. The prototype systems in ApHVAC only have a single room per system, but I need the system to be sized for and serve all of the rooms and not just the room with the thermostat. What is the easiest way to do this?

I am thinking I need to add rooms to the ApHVAC system template, ductwork connecting the rooms in parallel, and a controller to divide airflow among the different rooms. If I do it that way, will I still be able to use the auto-sizing functions with the new rooms?

Is there another way to "connect" the spaces so that ApHVAC thinks they are a single space, while still generating internal loads and following schedules defined individually?

Thanks in advance for some pointers..

Greg

[PCully]

Hi Greg,

I think normally this would be where a Multiplex is added over the room, in fact the prototype systems probably have the multiplex already defined and you just need to add as many layers as you require rooms.

In the Edit Multiplex dialog you have the option to assign rooms from room group and then when you choose the room group it adds as many layers as required for each room to be on a new layer.

I'd strongly encourage anyone trying to use the VE ASHRAE 90.1 PRM Navigator or ApacheHVAC to take training, I don't think it's really possible to just work through this process manually learning as you go and get any kind of meaningful result.

Phil

[enerGwizz]

Phil,

Thanks for the reply. I guess I should have explained more clearly... The two simplifications I was considering were:
1. to consolidate the spaces with different use types into one space to match the system zoning OR
2. to ignore the actual zoning of the systems and just provide the correct system type to EACH room

What I WANTED to find out was how to model the systems accurately, with each system actually serving several spaces but with the controlling thermostat in one. I DID figure out how to do it, but I wasn't able to use the multiplex because the number of spaces to each system varied. That became way more work than I wanted to put in.

What I ended up doing is option 2 above. I just used the multiplex tool for my 2 system types, and assigned ALL spaces served by each within the multiplex. This obviously isn't the most accurate because my model ended up with more systems than exist in the actual design, but it's how it would be simplified in other simulation tools like eQUEST, etc.

GC