[Bldg-sim] Cooling tower to chilled water (bypass chiller) free-cooling in eQuest?

Steve Mignogna smignogna at gmail.com
Wed Jun 11 10:42:26 PDT 2008


David,

I would set up your cooling tower with a heat exchanger and then in
your air-side system go to the "Cooling" tab.  Within that click on
the "Economizer" tab.  Turn on your water-side economizer and assign
the correct parameters to this tab (condensing loop, etc..).

If you need more specific help, please let me know.


--
Steve Mignogna
Atelier Ten

On Wed, Jun 11, 2008 at 11:47 AM, Edelstein, David
<Dedelstein at akf-eng.com> wrote:
> I am trying to model cooling tower water to chilled water free-cooling
> (bypass the chiller) in eQuest. If anyone has experience modeling this in
> eQuest it would be appreciated.
>
>
>
> Thanks in advance.
>
>
>
> David Edelstein, P.E.
>
>
>
>
>
> 1501 Broadway, Suite 700
>
> New York, NY 10036
>
> dedelstein at akf-eng.com
>
>
>
> D: 646-720-9863
>
> P: 212-354-5656
>
> F: 212-354-5668
>
>
>
> www.AKFGroup.com
>
>
>
> Arlington w Boston w New York w Philadelphia w Princeton w Stamford w Mexico
> City
>
>
>
> *********************************************** Important Notice
> *******************************************************
>
>
>
> 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 with 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 AKF.
>
>
>
> ********************************************************************************************************************
>
>  P Please consider the environment before printing this email.
>
> ________________________________
>
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Bill
> Sent: Thursday, March 27, 2008 3:35 AM
> To: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] FW: Ice storage chilling system - getting
> LEEDpoints?
>
>
>
> One thing to be careful of when considering the impact of low temperature
> air distribution on energy use:  Depending on climate, many hours of
> economizer cooling may be lost.  This can be a huge impact in mild climates,
> and should be evaluated in all climates that have moderate temperatures for
> at least a few months a year.  The increased plant energy use from the loss
> of "free" cooling can dwarf the air transport savings, unless this is
> accounted for in the design and control of the air systems.
>
>
>
> --Bill
>
>
>
> William E. Koran, P.E.
> Senior Engineer
> Q u E S T
> Quantum Energy Services and Technologies
> Voice: 503-557-7828
> Fax: 510-540-7268
> Web: www.quest-world.com
>
>
>
> ________________________________
>
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Keith Swartz
> Sent: Wednesday, March 26, 2008 7:04 AM
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] FW: Ice storage chilling system - getting LEED points?
>
> Bill makes a good point about taking advantage of the lower temperature of
> the ice system. I worked on a project that had an ice storage system that
> took advantage of the colder temperature. We made the chilled water supply
> temperature 38F and return temperature 62F (DeltaT=24F). The pumping power
> saved was pretty significant, since the chilled water had to be pumped
> underground more than 1200 feet from the Chiller Plant to the main building.
> The lower chilled water temperature allowed me to use lower supply air
> temperature at the air handlers, which allowed me to select smaller air
> handlers (due to lower cfm), which allowed me to actually fit the air
> handlers into the allotted space! So there are more benefits than just
> energy cost benefits…if you take advantage of the opportunities.
>
>
>
> Sincerely,
>
> Keith Swartz, PE, LEED(R) AP
>
> Energy Center of Wisconsin
>
> 455 Science Drive
>
> Suite 200
>
> Madison, WI 53711
>
>
>
> Phone: 608-238-8276 ext. 123
>
> Fax:     608-238-0523
>
> www.ecw.org
>
> The Energy Center of Wisconsin is an independent, nonprofit organization
> that seeks solutions to energy challenges.
>
> ________________________________
>
> From: William Bahnfleth [mailto:wbahnfleth at psu.edu]
> Sent: Sunday, March 23, 2008 1:36 PM
> To: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Ice storage chilling system - getting LEED points?
>
>
>
> I doubt that night-time wet bulb depression is sufficient in most places to
> compensate for the difference between saturated evaporating temperatures
> associated with typical chilled water and ice production systems.  However,
> break-even seems to be attainable for air-cooled systems.
>
> Variable speed compressors and thermal storage are a good match because VS
> operation maximized the impact of a lift reduction.
>
> A key to saving energy with ice storage or any other low temperature
> production scheme is to take advantage of the low temperature source.  The
> most common examples are low temperature water distribution and low
> temperature air distribution to achieve larger temperature differences and
> reduce transport energy consumption.
>
> Other benefits of  thermal storage that are significant, but frequently
> poorly quantified, if quantified at all, are load management effects--more
> efficient part loading, preferential loading of  more efficient equipment,
> etc.
>
> Bill Bahnfleth
>
> At 01:41 PM 3/23/2008, Wyman, Kevin L            UTPWR wrote:
>
> Content-class: urn:content-classes:message
> Content-Type: multipart/alternative;
>          boundary="----_=_NextPart_001_01C88D0D.0FE7F528"
>
> Agree with everything David pointed out. While ice making chillers would use
> more energy to create the colder temperatures needed for phase change, they
> often do this at night when cooling tower doesn't work as hard and ambients
> drop (in some climates) so net energy is often less. In other words, the kWh
> consumption can be less as well as peak kW savings under rate tarriff
> considerations.
>
>
> Kevin L. Wyman, P.E.
> LEED AP
> On-Site Power Product Management
> UTC Power
> 195 Governor's Highway
> South Windsor, CT 06074
> (860) 727-7020 (V)
> (860) 660-0723 (F)
> (860) 882-9595 (M)
> Kevin.wyman at utcpower.com
>
> ----- Original Message -----
> From: bldg-sim-bounces at lists.onebuilding.org
> <bldg-sim-bounces at lists.onebuilding.org>
> To: bldg-sim at lists.onebuilding.org <bldg-sim at lists.onebuilding.org>
> Sent: Sun Mar 23 09:32:47 2008
> Subject: Re: [Bldg-sim] Ice storage chilling system - getting LEED points?
>
> For EAC1, the comparison is about energy cost.  The ice storage will save
> money IF you have time-of-day electricity rates in place.  If you are using
> the EIA state average rate data, it won't show a savings.
>
> Ice storage actually uses more energy not less -- you can get more out of
> the ice, but remember that you have to spend the same amount of
> refrigeration energy to make the ice, plus the chiller will be working
> against unfavorable temperatures and fluid properties which will use more
> compressor energy compared to conventional chilled water, per ton-hr.
>
> Maybe there is merit if you can say what savings there are from night-time
> electricity compared to day-time electricity, or if there is some major
> problem with electricity distribution in your area.
>
> Your client may be interested in first cost savings if you design a partial
> storage system, but don't expect any LEED credit for that.
>
> David
>
> ________________________________
>
> From: bldg-sim-bounces at lists.onebuilding.org on behalf of Sasa Pantic
> Sent: Sat 3/22/2008 2:21 PM
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] Ice storage chilling system - getting LEED points?
>
>
> Dear colleagues,
>
> I would kindly ask for an information please.
> I am thinking of designing an ice storage chilling system that would
> generate ice at night, during low electricity rates, and will be used during
> the following day for to reduce peak cooling demands of the building.
>
> Could I get LEED credits in Energy and Atmosphere section for reducing the
> cooling cost?
>
> In addition, taking into account that ice can absorb more heat than that of
> water and therefore will lead to much more chilling capaciity or "tons" of
> refrigeration from the same size/horsepower rating of compressors than a
> conventional type of chiller.
> I gues I could get more LEED credits for being environmentally friendly?
>
> Please advise.
> Thanks muchly.
>
> Regards Sasa Pantic
>
>
>
> ________________________________
>
> Never miss a thing. Make Yahoo your homepage. <
> http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>
>
>
> _________________________________________________
>
>
>
> William P. Bahnfleth, PhD, PE, FASHRAE
>
> Professor of Architectural Engineering
>
> Director, Indoor Environment Center
>
>
>
> The Pennsylvania State University
>
> 104 Engineering Unit A
>
> University Park, PA 16802 USA
>
>
>
> voice: 814.863.2076 / fax: 814.863.4789
>
> e-mail:  wbahnfleth at psu.edu
>
> http://www.engr.psu.edu/ae/faculty/bahnfleth/
>
> http://www.engr.psu.edu/ae/iec/
>
> _________________________________________________
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>
>



-- 
Steve Mignogna
Atelier Ten



More information about the Bldg-sim mailing list