[Bldg-sim] Tall Bldg Pressurization & Stack Effect

[Varkie C Thomas]

Thanks for responses.  A group in Chicago is trying to evaluate air pressures and air movement in tall bldgs.  Burj Khalifa in Dubai is 162 floors and 828 meters tall and the apt floors with operable windows are the top - http://skyscrapercenter.com/dubai/burj-khalifa/  A proposed bldg is going to be taller (1,000 meters?). 

The attached preliminary Excel calculation sheet is my attempt to understand the issues of multi-use (retail, office, hotel, apartments, restaurants, services, etc.) high rise bldg.  I think the analysis should be based on vertical zones by floor usage type and floors served by a mechanical floor.  The air handling systems have to deal with infiltration due to stack effect of the vertical zones that they serve.

I have tried looking at CONTAM but I think it is too detailed for evaluating the performance of tall bldgs as a whole.  I think we need to develop a simpler modeling and simulation system for this purpose which can be linked to energy programs. 

Varkie
http://www.iit.edu/arch/faculty/thomas_varkie.shtml

>From 	Jon Hand <jon at esru.strath.ac.uk> 
Sent 	Wednesday, May 2, 2012 4:17 pm
To 	"thomasv at iit.edu" <thomasv at iit.edu> , "bldg-sim at lists.onebuilding.org" <bldg-sim at lists.onebuilding.org> 

Subject 	RE: [Bldg-sim] Tall Bldg Pressurization & Stack Effect

About ESP-r and tall buildings....

I know of no one who has attempted a super-tall building with ESP-r flow network. I was asked
one time about analysis of stack approaching 800m and my response then and now is that
this is SO FAR beyond the underlying correlations and research that a cautious
approach should include a substantial test and calibration phase. 

The mind-boggling number of leakage points would also be worth considering. Can
we safely ignore some classes of penetrations and facade faults? Are
crack models in current tools valid for the extreme pressure differences one might
encounter? It might require some new component representations.

And then there is the non-trivial issue that simulation tools work with single climate
files - over that vertical distance one might reasonably expect there to be
several different weather patterns (temperatures, wind speeds and directions)
and so it might be necessary to adapt tools to deal with multiple sets of boundary
conditions. And there might be rapid fluctuations, so hourly weather patterns is
unlikely to provide a rich enough set of disturbances.

And most network flow codes assume that air is incompressible. That 'shortcut' helps
the solution and probably does little damage in models of moderate complexity
and it might not be valid in the context of super-tall.

Conceptually it might work and I would say there are a lot of caveats to resolve
and probably a substantial investment needed to be able to confidently approach
such projects. And the teams that have implemented super tall buildings also
will have skills and methods that us mortals do not.... Not territory for novices.

Regards, Jon Hand

From: bldg-sim-bounces at lists.onebuilding.org [bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Varkie C Thomas [thomasv at iit.edu]
Sent: 02 May 2012 20:01
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Tall Bldg Pressurization & Stack Effect

Is COMIS still active? How is it used within EnergyPlus? Can it be used to evaluate building pressurization and stack effect infiltration in multiuse (retail, office, hotel with fixed windows and apts at the top with operable windows) tall and super-tall bldgs (ex. 160 storey Burj Khalifa and proposed Jeddah Kingdom Tower)? Can ESPr and IESVE be used to evaluate bldg pressurization and stack effect infiltration in super-tall bldgs? Is CONTAM linked with an energy program?

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