[EnergyPlus_Support] Summary of inaccuracies simulating atria. Are they correct?

[David Barrera <davidabraham_b@xxxxxxxxx>]

I?ve read mails and information in the E+ yahoo group
about atria and comfort simulations and I need to
verify I have not misunderstood: 

I´m starting the characterization of a 10 sotories
building and at this point i have two questions:

1) Is it possible to create two contiguous zones in
such a way that there is no surface dividing these two
zones? I want to do this to visualize the difference
between thermal comfort of those people who works next
to the windows and those who works in the core of the
building, away from sunlit windows.

Michael J Witte wrote: 

1.	With and inter zone window you can pass solar
radiation between zones, but will be no convective
exchange. 

2.	Defining Mixing, Cross Mixing models you can have
convective exchange, but radiant exchange will not be
present. 

Andy Tindale wrote about atria and AirflowNetwork
model:

There are basically two possible approaches when
modeling tall spaces such as atria using
EnergyPlus/AIRNET (or any other simulation program
coupled with multi-zone airflow simulators):

1. Model the atrium as a single tall space or,

2. Model the atrium as a series of horizontal slices
with air flow connections between them.

Option 1, where the atrium is modeled as a single
space is the best option when using EnergyPlus/AIRNET
because: 

1.	There?s no reliable way to get solar radiation pass
through multiple horizontal slices in the general
case. 

2.	AIRNET openings are assumed to be LVO (Large
Vertical Openings) and for openings that are
horizontal or near horizontal (LHO) no claims for
accuracy are made.

I understand from this that any simulation in which I
don?t enter gradient temperatures or another kind of
information about the stratification in the space will
have an inaccuracy because of ignoring either radiant
or convective exchange between zone (both at the same
time can not be considered). Is that correct? In fact
the effect of define the ?holes? in each floor so we
can build the atrium seem to be null, isn?t it? 

When Nichole Chen mailed asking about ?how to simulate
an atrium and its adjacent zones? the answer was to
define inter zone walls. If an inter zone element is
defined twice, once for each zone, this means that I
should define the inter zone wall for 1) the adjacent
office, and 2) what other zone? If I had an atrium of
5 floors, and following the suggestion of considering
the atrium as a single zone, I would have 20 walls to
define just one zone (4walls x 5 levels)? I don?t
know, I don?t get very well this point. 

Thanks a lot. 



 
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