[Bldg-sim] Tall Bldg Pressurization & Stack Effect

[Chuck Khuen]

We will soon be able to offer wind speed and direction at about every 250 M 
of altitude for anywhere if this helps.

Best, Chuck

_________________
Chuck Khuen
Principal
Weather Analytics Inc.
781-856-5383

-----Original Message----- 
From: Varkie C Thomas
Sent: Thursday, May 03, 2012 10:00 AM
To: Jon Hand
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Tall Bldg Pressurization & Stack Effect

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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