[esp-r] Re: Suggestions for Double Facade Modeling

[Diaz, Camilo]

Hi Omer

I am interested in the strategy you describe (more the design than the modelling) and would like to hear about the results when they come out if possible. From intuition it could be argued that a double façade cavity will get warmer than the outside  - or at best the same as ambient - therefore adding to the building loads. Perhaps this is more a winter driven strategy? Again with good glazing you probably get rid of most heating loads in such climate. Then again you never know, that's why we go to the trouble of modelling these things. I would be interested in the key headlines of the outcome if possible?

 

Thanks

 

Camilo 

0207 314 4447 

07713 985 845

 

From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-bounces at lists.strath.ac.uk] On Behalf Of Geissler Achim
Sent: 21 June 2012 10:58
To: esp-r at lists.strath.ac.uk
Subject: [esp-r] Re: Suggestions for Double Facade Modeling

 

Dear Ömer

 

basically, you will want to model the facade cavity as a set of stacked zones. Also, you will probably want to have more than one zone in the width (ideally in the depth, as well, to allow for different directions of flow along the inner and outer skin of the facade cavity. If the corners of the building are also open, as it seems to be, it may be interesting to really have a set of zones enveloping a central "building". The standard maximum number of zone is 82, so this may be a limit.

 

For the stack, you could split the height of the building into maybe 4 to 10 segments, for the width per façade 2 segments. This would give you 32 to 80 zones (so 10 in the stack would already be close to the limit) without a split in the depth. With a split in the depth, a stack of 4 would lead to a total of 64 zones. The actual building could be "a few zones", however, then be aware that the detail of results is also very limited and you will need to add appropriate thermal mass and internal loads.

 

If you expect cross-flow and "around the corner flow" in the façade cavity to be negligible, of course looking at one façade elevation only would greatly reduce the number of zones or allow for higher detailing of zones. You could turn the model via script for calculations in all directions.

 

The "best" approach will strongly depend on the most important issues to be studied.

 

Best

Achim

 

 

 

 

Von: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-bounces at lists.strath.ac.uk] Im Auftrag von Ömer Moltay
Gesendet: Mittwoch, 20. Juni 2012 22:05
An: esp-r at lists.strath.ac.uk
Betreff: [esp-r] Suggestions for Double Facade Modeling

 

Dear esp-r Users,

We would like to simulate a 43 storey high office building (located in a Mediterrenean climate) with double facade for energy calculation purposes. The double facade is a single cavity on all four sides of the building and from first floor to the top floor.  The depth of the cavity ranges between 3 - 5 meters. The design intent is to ventilate it via thermal buoyancy and also operable windows on the exterior skin (automatic control). No natural ventilation of the office interiors or night time cooling is foreseen at the moment. We would like to analyse the best ways of design and operation and see how much we can decrease the HVAC cooling / heating running costs.

We intend to use esp-r and DOE/eQuest for this. I would appreciate any suggestions on how to approach this task. 

Thank you,

Ömer Moltay, LEED AP BD+C, ASHRAE BEMP, CPMP, BREEAM Assessor 
Mimta EkoYapi
Hekimsuyu Cad. 559. Sk. No:39 
34255 Kucukkoy Istanbul Turkey 
Tel: 90-212-617-2296 
Fax: 90-212-617-2297 
www.eko-yapi.net <http://www.eko-yapi.net/>  

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