[Equest-users] Output of Space cool consumption comes innegative

Tue May 10 07:29:51 PDT 2016

Hi Nick,

Thanks for your response.
This is the first project where I have had to use System 8 (VAV with PFP Box) and I want to ensure that I am indeed modeling it per the guidelines.

I am using Power Induction Unit (PIU) with chilled water cooling and electric heating with electric reheat. Also, I have Zone Terminal Type as Parallel PIU(at zone level). And have zone fan ratio at 0.5 and zone fan power at 0.00035 kW/cfm .

My main concern is still with fan energy. Do I still model system level fan power per Appendix G3.1.2.9 guidelines?

Bikesh

From: Nicholas.Caton at schneider-electric.com [mailto:Nicholas.Caton at schneider-electric.com]
Sent: Tuesday, May 10, 2016 10:06 AM
To: Bikesh Dahal; Nicholas.Caton at schneider-electric.com; eee.javed at gmail.com; nitin.harjai28 at gmail.com
Subject: RE: [Equest-users] Output of Space cool consumption comes innegative

Hi Bikesh,

Rest assured, the community/membership of this mailing list has collective experience tackling every baseline system type.

You will however need to provide a more detailed/specific query to receive a targeted response.  Let us know what issue you are having, what you understand so far about the problem, what you have tried & observed, etc… that will help others help you.

Based on your subject header, I’ve copied below a (recent) similar discussion where I provided an outline of typical causes for negative space cooling consumption.  Do be aware of & bookmark the onebuilding archives as a resource – particularly those for [eQuest-users]<http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/> & [Bldg-sim]<http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/> ;-).

~Nick

------------------------------------------------------------------------------------------------------------------------------
Nick Caton, P.E.
  Senior Energy Engineer
  Energy and Sustainability Services
  North America Operations
  Schneider Electric

D  913.564.6361
M  785.410.3317
E  nicholas.caton at schneider-electric.com<mailto:nicholas.caton at schneider-electric.com>
F  913.564.6380

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

[cid:image001.png at 01D189AB.58634A10]

From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bikesh Dahal via Equest-users
Sent: Monday, May 09, 2016 1:51 PM
To: Nicholas.Caton at schneider-electric.com<mailto:Nicholas.Caton at schneider-electric.com>; eee.javed at gmail.com<mailto:eee.javed at gmail.com>; nitin.harjai28 at gmail.com<mailto:nitin.harjai28 at gmail.com>
Cc: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Output of Space cool consumption comes innegative

Hi everyone,

Anyone has experience using System 8 from ASHRAE 90.1- VAV with PFP. Any advice/suggestions would be greatly appreciated. ?

Bikesh

From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Nicholas.Caton at schneider-electric.com<mailto:Nicholas.Caton at schneider-electric.com>
Sent: Tuesday, March 29, 2016 10:00 AM
To: eee.javed at gmail.com<mailto:eee.javed at gmail.com>; nitin.harjai28 at gmail.com<mailto:nitin.harjai28 at gmail.com>
Cc: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Output of Space cool consumption comes innegative

Hi Nitin,

I suspect there are inadvertent changes beyond those you’ve described moving CFM’s around.  Comparing a before/after save file case could prove enlightening if that’s available.

I searched the archives a bit – past instances of  “negative cooling” have reportedly involved:

-          Misapplied CHW loop reset scheduling

-          Drastically undersized chiller capacities (review units, try auto-sizing)

-          Drastically undersized heat rejection / towers, in a similar vein

-          Custom chiller curves gone awry

Some other observations, beyond the negative cooling:

-          Electric heating is more than doubling

-          Electric fan energies are altogether slightly higher

-          Gas heating is a full magnitude larger

From the above I’d suspect one or more edits to inputs on the hydronic side are playing a role…

Best regards,

~Nick

---------------------------------------------------------------------------------------------------------------------------------------------
Nick Caton, P.E.
  Senior Energy Engineer
  Energy and Sustainability Services
  North America Operations
  Schneider Electric

D  913.564.6361
M  785.410.3317
E  nicholas.caton at schneider-electric.com<mailto:nicholas.caton at schneider-electric.com>
F  913.564.6380

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

[http://10.218.104.225:8090/Images/SE.comCapsule.png]<http://www.schneider-electric.com/ww/en/>

[cid:image002.png at 01D189A1.14B548E0]

*Please consider the environment before printing this e-mail

From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Javed Iqbal
Sent: Monday, March 28, 2016 11:45 AM
To: Nitin Harjai
Cc: equest-users
Subject: Re: [Equest-users] Output of Space cool consumption comes innegative

Would you mind sharing your INP and PD files?

On Mon, Mar 28, 2016 at 10:13 PM, Nitin Harjai <nitin.harjai28 at gmail.com<mailto:nitin.harjai28 at gmail.com>> wrote:
Hi...

I have a problem regarding the equest output & I need your help so that I can complete the project on time.

At the first step to remove the proposed case unmet hours,i have increased the cfm of same zone by diverting the cfm of other zone which is having zero unmet hour, in order to maintain the design CFM of particular system throughout the model.

After simulate the model, the unmet hour of same zone has been reduced without affecting the zone from where the CFM was diverted, but the output of space cool consumption comes in negative. I have attached the pics of before & after the simulation of monthly energy consumption graph.
I just want to know that why is this space cool output consumption showing in negative and how to make it correct?

For your information, this is the hospital project consist of  ground+7 floors+3 basements and for cooling & heating, there are two water cooled screw chiller, two hot water generator are used on site.

Regards,
Nitin Harjai
Sustainability Engg.

_______________________________________________
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>

--

Javed Iqbal, LEED AP, CEA
Sr. Energy Analyst

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
______________________________________________________________________

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20160510/e009d0d8/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 7893 bytes
Desc: image001.png
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20160510/e009d0d8/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.gif
Type: image/gif
Size: 1822 bytes
Desc: image002.gif
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20160510/e009d0d8/attachment-0002.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.png
Type: image/png
Size: 5423 bytes
Desc: image003.png
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20160510/e009d0d8/attachment-0005.png>