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Thermal Zones that are open to the outdoor environment [closed]

asked 2021-01-14 03:43:02 -0500

updated 2021-03-29 08:51:11 -0500


I am currently modeling an University building and the Atrium is partially open to the outdoor environment. For those boundary surfaces I have used the "Air Wall" construction, which is then converted into the Construction:AirBoundary object (EnergyPlus 9.3).

Nevertheless, when I make the simulation run I get an error saying that the Air Boundary object cannot be used for outer surfaces. Effectively, the I/O Reference reports the following:

"Construction:AirBoundary indicates an open boundary between two zones. It may be used for base surfaces and fenestration surfaces. When this construction type is used, the outside boundary condition of the surface must be either surface or zone."

So, here is my question: how can I model the boundary surfaces of a zone that is directly connected to the outdoor environment?

One potential solution I have thought about (although I do not really like it) is to add windows to those surfaces and let them be open all of the time. Is there anything a bit more "elegant" that I can use instead of the solution I have found?

Many thanks

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Closed for the following reason the question is answered, right answer was accepted by Martu
close date 2021-01-20 05:26:23.388857

1 Answer

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answered 2021-01-19 13:14:50 -0500

My approach is:

  • do not model Atrium as a thermal zone (as it is open to outdoor I guess it is not a conditioned zone , that it it has not HVAC systems)

  • to model Atrium surfaces as Shading surfaces to properly take into account shadowing , as wella as outdoor temperature as boundary conditions for thermal zones facing the Atrium

  • If there are lights/electrical equipment, and more generally consumptions related to Atrium, set them into the model through External Equipment objects

I hope it helps


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Yes, that was the other option. I just wanted to have a bit more control over that space. But, at the moment, I think it's probably the best solution.

Many Thanks

Martu gravatar image Martu  ( 2021-01-20 05:25:19 -0500 )edit


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Asked: 2021-01-14 03:43:02 -0500

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Last updated: Jan 20