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Is it possible to add multiple air loops to one thermal zone?

asked 2015-04-16 20:01:09 -0500

MatthewLynch's avatar

updated 2017-05-03 19:16:01 -0500

I am modeling a large manufacturing floor with about 26 package roof top units (average ~20 tons each). I have the facility floor as one thermal zone and thus would need to add 26 Package Roof top units to this one thermal zone.

However, in Open Studio, when I go to add this thermal zone to a new package roof top unit it deletes the thermal zone from the previous package rooftop unit.

My question is, is it possible to have multiple air loops feeding one thermal zone? If not, is there a different way I should thermally model the large facility floor?

Thank you,


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answered 2015-04-16 20:54:49 -0500

updated 2015-04-16 20:56:40 -0500

EnergyPlus only allows one air loop per zone. Combining the units is common, although if your building is one large space, the perimeter zones may have to work harder than the core, so you may want to still make multiple zones. You can always add zone mixing objects in between the zones to add some interaction between them.

If you are conditioning with zone equipment instead of air loops, you can have multiple pieces of equipment.

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Thank you David,

I had a follow up question: by 'combining the units' you mean representing multiple package rooftop units as one. Thus, in this case, a 'single cooling coil DX' unit would represent 26 package units?

I will most likely go the route of creating many zones because of the size of the space, but I wanted to clarify the above point for my understanding.

If I were to condition the thermal zone with zone equipment, it seems that my only option would be multiple PTAC/PTHP units but those would not represent my 20 ton RTU's well. Would I be wrong in saying that?

Thank you!

MatthewLynch's avatar MatthewLynch  ( 2015-04-17 09:33:44 -0500 )edit

answered 2015-04-16 20:21:48 -0500

If all the equipment will divide the load, I think you can model all the units as only one unit with the same performance characteristics of the each unit.

I have a similar problem, but in my case I need to model two different systems (a water cooled and a VRF) to attend the same thermal zone in differents schedules.

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Asked: 2015-04-16 20:01:09 -0500

Seen: 622 times

Last updated: Apr 16 '15