[TRNSYS-users] Atrium and natural ventilation

[David Bradley]

Christophe,
   I would think that the correct method for simulating the atrium 
stratification would be to break the atrium up into multiple zones. You 
will then be faced with two problems. First is how to make sure that any 
solar energy can pass through the virtual zone boundaries. The other is to 
assess the air flow between the virtual zones. The first problem can be 
solved if you break the atrium up into only two zones because Type56 is 
able to define an internal window that can pass solar from one zone to 
another. I believe, however, that it cannot assess multiple internal 
windows in series. Thus if you broke the atrium up into 3 zones, the bottom 
zone would not get any solar. Someone please correct me if I am wrong about 
that!

   The problem of air flow is best addressed by using one of the 
connections between TRNSYS and either COMIS or CONTAM. Those bulk air flow 
modeling tools will give you an estimate of the air flow between the 
virtual zones based on temperature and pressure differences between the 
zones. The COMIS connection is implemented either through TRNFlow or 
through Type157. The CONTAM connection is implemented through Type97.
Kind regards,
  David


At 11:21 10/5/2006, Enertech wrote:
>Dear TRNSYS users
>
>We’re working on a office building with passivhaus objectives : no air
>conditioning plant and very low heating consumption (less than 15
>kWh/m²/year). This building has an atrium high 12 m. I’ve got two problems:
>-         How to model the temperature stratification in the atrium? It is
>a unique volume but we can assume that the temperature won’t be the same in
>all the volume. Should I describe this atrium as 2 or 3 zones and add a
>coupling airflow between them?
>-         We want to use night free cooling to cool the offices during the
>night in summer. It won’t be transversal ventilation but each single office
>will be ventilated by one unique window, that we assume wide opened
>(dimensions 60 x 170 cm). Is there a type in TRNSYS that enable to model
>natural ventilation?
>
>Thanks a lot for your help,
>
>Best regards,
>
>Christophe Plantier
>
>
>===========================
>ENERTECH
>F-26160 FELINES SUR RIMANDOULE
>tel-fax : 04 75 90 18 54
>Email : sidler at club-internet.fr
>Web  : http://sidler.club.fr
>================================
>
>
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