[Equest-users] Query regarding PDEC ( Passive cooling ) simulation in eQuest

Joe Huang yjhuang at whiteboxtechnologies.com
Thu Mar 8 11:05:25 PST 2012


Mansi,

If CoolT is as Vikram describes, this might be the solution to your problem.  The main 
issue for you is to know the air flow output of the PDEC  in actual operations, not under 
design conditions, so that other program you mentioned for sizing the PDEC is of little 
help.  If CoolT is not able to give you air flow rates based on the ambient conditions and 
the indoor air temperature, you could try building a simple two-zone model (PDEC, 
Building) using CONTAM and then run that stand-alone to get the air flows between the two 
zones.

In reference to Vikram's comment, I've said all along that the difference between the PDEC 
and a  standard DEC
is the mechanism used to drive the air across the media - using natural bouyancy forces in 
the first case and a mechanical fan in the second case.  Once you have the air flow rate, 
the PDEC is actually simpler to model because there's no need to model fan efficiency and 
heat gain, etc.  In fact, it just takes a single effectiveness curve, or even just a 
constant effectiveness number.

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
www.whiteboxtechnologies.com
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"


On 3/8/2012 6:49 AM, Mansi Jayswal wrote:
>
> Thanks Vikram,
>
> Could you tell me from where i can download this Software  " CoolT" ? i have tried 
> to Google but did not find it anyware. I have even found one of your research paper. it 
> seems you have already worked on it. it will be great if you could guide me.
>
>
>
> On Thu, Mar 8, 2012 at 7:37 PM, Sami, Vikram <Vikram.Sami at perkinswill.com 
> <mailto:Vikram.Sami at perkinswill.com>> wrote:
>
>     Another option to look into is CoolT developed by Nader Chalfoun at University of
>     Arizona in Tucson. It’s a Dos program that is based on empirical data that they
>     collected from the extensive testing they did on Cool Towers (Passive Downdraught
>     Chimneys).
>
>     Again – I would throw in words of caution. Passive downdraught chimneys rely on
>     buoyancy driven forces – something that you cannot approximate with a fan driven
>     evaporative cooler or wind driven. eQUEST might be able to model this, but its
>     beyond my knowledge. Also – The folks at UA (Nader Chalfoun & Martin Yoklic) did
>     some testing with cool towers in enclosed spaces. I would try writing to them to get
>     some feedback on issues to consider.
>
>     I think Nader is on this list – not sure if he’s still active.
>
>     **
>
>     *Vikram Sami*, LEED AP BD+C
>
>     Sustainable Design Analyst
>
>     1315 Peachtree St. NE, Atlanta, GA 30309
>
>     t: 404-443-7462    f: 404.892.5823     e: vikram.sami at perkinswill.com
>     <mailto:vikram.sami at perkinswill.com> www.perkinswill.com <http://www.perkinswill.com/>
>
>     *Perkins+Will.*Ideas + buildings that honor the broader goals of society
>
>     *From:*Mansi Jayswal [mailto:ar.mansi.jayswal at gmail.com
>     <mailto:ar.mansi.jayswal at gmail.com>]
>     *Sent:* Thursday, March 08, 2012 2:40 AM
>     *To:* Design Builder USA
>     *Cc:* Dahlstrom, Aaron; Sami, Vikram; equest-users at lists.onebuilding.org
>     <mailto:equest-users at lists.onebuilding.org>
>
>
>     *Subject:* Re: [Equest-users] Query regarding PDEC ( Passive cooling ) simulation in
>     eQuest
>
>     Thank you all for your quick response and Information.
>
>     Is it possible that if i use PHDC software to design the PDEC system and simulate
>     the same building in eQuest ??  PHDC software can give me the required size of the
>     passive down draught evaporating cooling towers for the building.
>
>     On Wed, Mar 7, 2012 at 9:37 PM, Design Builder USA <jcrossett at designbuilderusa.com
>     <mailto:jcrossett at designbuilderusa.com>> wrote:
>
>     You may wish to explore the free trial of Design Builder, as it has CFD, natural
>     ventilation and evaporate cooling.
>
>     Tho I am not sure if it can be used for your passive cooling requirement or not..
>
>     Best of luck
>
>     On Wed, Mar 7, 2012 at 6:53 AM, Dahlstrom, Aaron <ADahlstrom at in-posse.com
>     <mailto:ADahlstrom at in-posse.com>> wrote:
>
>         Mansi –
>
>         We have done some schematic modeling of wind towers with Fluent, a CFD package
>         as noted.
>
>         Our climate didn’t justify evaporative pre-cooling.
>
>         eQUEST has a natural ventilation module, which I have not fully dived into.
>
>         I believe it requires inputs that would likely be validated by a CFD model – for
>         example, I don’t think eQUEST’s natural ventilation model allows for evaporative
>         pre-cooling as a temperature driver for natural air exchange in a space.
>
>         As eQUEST models each zone as a fully mixed space, and has limited air transfer
>         between zones, you may also have trouble getting the thermal stratification from
>         eQUEST that would typically be needed to drive natural ventilation in a PDEC.
>
>         *Aaron Dahlstrom , PE, LEED® AP*
>
>         *In P**o**sse*– A subsidiary of*AKF*| 1500 Walnut Street, Suite 1414,
>         Philadelphia, PA 19102
>
>         d: 215-282-6753 <tel:215-282-6753>| m: 267-507-5470 <tel:267-507-5470>| In
>         Posse: 215-282-6800 <tel:215-282-6800>| AKF: 215-735-7290 <tel:215-735-7290>
>
>         e: ADahlstrom at in-posse.com <mailto:ADahlstrom at in-posse.com> | in posse web:
>         www.in-posse.com <http://www.in-posse.com/> | akf web: www.akfgroup.com
>         <http://www.akfgroup.com/>
>
>         *From:*equest-users-bounces at lists.onebuilding.org
>         <mailto:equest-users-bounces at lists.onebuilding.org>
>         [mailto:equest-users-bounces at lists.onebuilding.org
>         <mailto:equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Sami, Vikram
>         *Sent:* Wednesday, March 07, 2012 8:53 AM
>         *To:* Mansi Jayswal; equest-users at lists.onebuilding.org
>         <mailto:equest-users at lists.onebuilding.org>
>         *Subject:* Re: [Equest-users] Query regarding PDEC ( Passive cooling )
>         simulation in eQuest
>
>         Mansi,
>
>         I doubt you can do this credibly in eQUEST. You really need a CFD type package
>         to be able to simulate this. . A word of caution – the effort to develop the
>         simulation for this is a master’s thesis in itself.
>
>         **
>
>         *Vikram Sami*, LEED AP BD+C
>
>         Sustainable Design Analyst
>
>         1315 Peachtree St. NE, Atlanta, GA 30309
>
>         t: 404-443-7462 <tel:404-443-7462>    f: 404.892.5823 <tel:404.892.5823>     e:
>         vikram.sami at perkinswill.com <mailto:vikram.sami at perkinswill.com>
>         www.perkinswill.com <http://www.perkinswill.com/>
>
>         *Perkins+Will.*Ideas + buildings that honor the broader goals of society
>
>         *From:*equest-users-bounces at lists.onebuilding.org
>         <mailto:equest-users-bounces at lists.onebuilding.org>
>         [mailto:equest-users-bounces at lists.onebuilding.org]
>         <mailto:[mailto:equest-users-bounces at lists.onebuilding.org]> *On Behalf Of
>         *Mansi Jayswal
>         *Sent:* Tuesday, March 06, 2012 11:25 PM
>         *To:* equest-users at lists.onebuilding.org <mailto:equest-users at lists.onebuilding.org>
>         *Subject:* [Equest-users] Query regarding PDEC ( Passive cooling ) simulation in
>         eQuest
>
>         Hello friends,
>
>         My name is Mansi Jayswal. I am a final year student of Masters Programme at CEPT
>         University, India. By profession I am an architect. Currently I am doing thesis
>         on passive cooling technique (Passive down draught evaporative cooling system-
>         PDEC ). And try to identified that how much cooling load of HVAC system can be
>         replaced through this system.
>
>         Now my query is that is it eQuest is capable to simulate such building with wind
>         tower or PHDC (PDEC ) system? If anybody knows please kindly reply. I have very
>         days left for final submission and I am stuck here.
>
>         Thanks
>
>         -- 
>
>
>         Regards,
>
>         Mansi Jayswal,
>
>         B.Arch I IGBC AP I M.Tech in Climate Change & Sustainable Development
>
>         Faculty of Sustainable Environment & Climate Change,
>
>         Centre for Environmental Planning & Technology (CEPT) University
>
>
>         This e-mail may contain information that is confidential, privileged or
>         otherwise protected from disclosure. If you are not an intended recipient of
>         this e-mail, do not duplicate or redistribute it by any means. Please delete it
>         and any attachments and notify the sender that you have received it in error.
>         Unintended recipients are prohibited from taking action on the basis of
>         information in this e-mail. E-mail messages may contain computer viruses or
>         other defects, may not be accurately replicated on other systems, or may be
>         intercepted, deleted or interfered without the knowledge of the sender or the
>         intended recipient. If you are not comfortable with the risks associated with
>         e-mail messages, you may decide not to use e-mail to communicate with In Posse.
>
>         _______________________________________________
>         Equest-users mailing list
>         http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
>         To unsubscribe from this mailing list send  a blank message to
>         EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
>         <mailto:EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG>
>
>
>
>     -- 
>
>     Jeremiah D. Crossett
>
>     Energy Modeling Consultant
>
>     503-688-8951
>
>     www.DesignBuilderUSA.com <http://www.DesignBuilder.com>
>
>
>
>     -- 
>
>
>     Regards,
>
>     Mansi Jayswal,
>
>     B.Arch I IGBC AP I M.Tech in Climate Change & Sustainable Development
>
>     Faculty of Sustainable Environment & Climate Change,
>
>     Centre for Environmental Planning & Technology (CEPT) University
>
>
>
>
> -- 
>
> Regards,
> Mansi Jayswal,
> B.Arch I IGBC AP I M.Tech in Climate Change & Sustainable Development
> Faculty of Sustainable Environment & Climate Change,
> Centre for Environmental Planning & Technology (CEPT) University
>
>
> _______________________________________________
> Equest-users mailing list
> http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20120308/f5af95e0/attachment-0002.htm>


More information about the Equest-users mailing list