Energy Pro 6

I'm starting to model a hotel in Energy Pro and it's kicking my a$$.

30 VRF CU's, roughly 170 guest rooms, natural ventilation, corridor supply, the hotel is actually 2 historic buildings (one wood, one concrete. I feel like this is going to take ages.

Can you combine rooms of similar type and exposure? I've done that in trace and equest before.

I was thinking about that too. That's how it is in trace. I have CU-1, 2 and 3 serving the "same" type of rooms CU-1 for floors 2 and 3, CU-2 for 3 and 4, CU-3 for floors 5 and 6.

But the thing is when you enter the CU's in Energy Pro 6 you need to add the refrigerant piping line length in order for the Energy Pro calculations to derate the system accordingly.

I'm using LG LATS multi-V and I just took the worst case scenario for CU-1, CU-2 and CU-3 in terms for refrigerant piping length but I don't think cutting corners for energy modeling would be acceptable since a code official will be reviewing it. Currently I'm halfway through this video and it seems to be helping me understand a little bit better.

>https://www.youtube.com/watch?v=tMrVUcOdUfY

That seems over the top detail. How much does the refrigerant piping length derate the system?

I just spoke with the other PE on staff that has done this and he said to account for each individual system.

I personally think it would be OK but the thing, that i forgot, is that the exterior concrete walls change in size as you go up in floors...I'm trying to find short cuts but each is coming to a dead end. bwah bwah

If I were doing an energy study I'd combine them and not worry about the change in width change and use an average. If I was designing I'd combine like rooms by zone and make conservative assumptions. It all depends on what you are trying to accomplish.