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What is the best practice to model an large space in EnergyPlus by using Multi-zone method?

I want to get the energy and temperature in different areas of the big space(without using CFD). However I still don't have a clear idea what is the best way of modeling it. I am looking for recommendations on:

1)Preparing geometry: Should we split the large zone into small mult-zones? Is that even make sense considering the EnergyPlus will transfer the radiation as diffuse radiation between the zones? Is natural ventilation simulated correctly?

I simulated the load in different areas.The results of my simulation seem to be untrue.The load on the inter-zones is significantly smaller than the outer zones, and the gap is large, which seems strange.

xianxian's avatar
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xianxian
asked 2019-09-04 08:02:36 -0500
__AmirRoth__'s avatar
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__AmirRoth__
updated 2019-09-29 10:13:35 -0500
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Since the equations that are solved by AirflowNetwork (and other similar tools) can't represent the gradient phenomenon that are common in large spaces, getting a reasonable solution out of them by subdividing a volume is a pretty chancy business at best. Accordingly, there's not much in the way of best practices, other than perhaps "don't do this". So the answers to your questions are: no, no, and no.

With that said, if you know what the flows should look like it is possible to construct a network that gives plausible results and might match up acceptably to more detailed results (i.e. CFD). But you have to know what the flow will look like, and it won't be a substitute for a CFD simulation.

Jason DeGraw's avatar
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Jason DeGraw
answered 2019-09-06 10:11:08 -0500
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Thank you very much for your reply. If using multi-zone method partitioning to simulate large space is not a good method, do you have any suggestions to simulate large space energy consumption? I still look forward to simulating energy consumption in different areas.

xianxian's avatar xianxian (2019-09-08 20:50:33 -0500) edit

If I use the CFD to calibrate the Roomair model, can I simulate the vertical and horizontal loads of large spaces? (I mainly want to simulate the horizontal load) Thank you very much for your answers.

xianxian's avatar xianxian (2019-09-08 21:09:50 -0500) edit

CFD+RoomAir might work for what you are looking for. I'm not an expert on the details of the RoomAir model, though, so I'd suggest checking the documentation and example files pretty closely.

Jason DeGraw's avatar Jason DeGraw (2019-09-09 12:20:48 -0500) edit
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