[Equest-users] DHW loads difference

[Julien Marrec]

Pramod,

Nathan has a good theory, I would test that out!

If that doesn't solve it, I'm afraid you'll have to share the .inp files if
you want more help.

Best,
Julien

--
Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13

LinkedIn (en) : www.linkedin.com/in/julienmarrec
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
<http://www.linkedin.com/in/julienmarrec>

2015-01-12 14:55 GMT+01:00 Nathan Miller <nathanm at rushingco.com>:

>  My guess is that it is the standby losses making the difference. You
> presumably have the tanks assigned to a zone. If there is a difference in
> envelope, lighting loads, plug loads, etc in that zone between the two
> runs, then it might affect the standby losses (because the delta-T in the
> space could be different). If you want to test that theory, assign the DHW
> heater to be “Outdoor” in both runs, that way standby losses should be
> identical. If the energy use aligns, you will know it was standby loss
> making the difference. If they are still different, it is something else
> (schedule, peak gpm, DHWH efficiency, etc).
>
>
>
>
>
> *Nathan Miller, PE, LEED AP BD+C** – **Mechanical Engineer/Senior Energy
> Analyst*
>
> *RUSHING* | *D* 206-788-4577 | *O* 206-285-7100
>
> *www.rushingco.com <http://www.rushingco.com/>*
>
>
>
> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
> Behalf Of *Pramod .D
> *Sent:* Monday, January 12, 2015 8:42 AM
> *To:* Byron Burns; equest-users at lists.onebuilding.org
> *Subject:* Re: [Equest-users] DHW loads difference
>
>
>
> Byron,
>
>
>
> Thanks for your immediate reply. I have compared all the schedules,
> volume, capacity, tanks loss, etc. Everything is same but I am getting
> difference in results. Please help me out on this and thanks for the manual.
>
>
>
> Thanks,
>
>
>
> *Pramod D* | * Junior Energy Analyst*
>
> *d.pramod at setty.com <d.pramod at setty.com>*
>
>
>
> *From:* Byron Burns [mailto:B.Burns at ha-inc.com <B.Burns at ha-inc.com>]
> *Sent:* Monday, January 12, 2015 7:04 PM
> *To:* Pramod .D; equest-users at lists.onebuilding.org
> *Subject:* RE: DHW loads difference
>
>
>
> Hello Pramod,
>
>
>
> You should be able to get the results to line up, if you are interested in
> the algorithm used, here
> <http://doe2.com/download/DOE-21E/DOE-2EngineersManualVersion2.1A.pdf> is
> a link to the engineering manual.  Generally, the DHW energy is modeled
> just like a process load with a few more knobs (hourly demand * fractional
> schedule)/DHW efficiency + standby loss.  There is a portion of the
> calculation that accounts for the tank loss, which is a factor of the size
> of the tank, the amount of insulation on the tank and the ambient
> conditions, so make sure both the baseline and proposed models have the
> same volume, amount of insulation and are located in the same zone.
>
>
>
> To ensure it is not something simple, I would recommend re-inputting the
> data and running it again.  You will notice that eQ rounds many of the
> inputs in the GUI, however it will input the actual values into the .inp
> file and .bld file when you run it, so make sure all inputs are the same
> regardless of how they are displayed.  Also the schedules are a common
> cause of these issues.  I recommend using something to compare the inputs
> of both your baseline and proposed .inp files to ensure they are the same.
> Personally, I like Notepad++, <http://notepad-plus-plus.org/> it has a
> compare plug in that makes it a snap.
>
>
>
> Hope that helps,
>
>
> *Byron D. Burns, EIT, BEMP*
> Energy Engineer, Building Sciences Studio
>
> *H&A | Hankins & Anderson* | www.ha-inc.com
> *d:* (804) 420-1622 *p:* (804) 285-4171 *f:* (804) 217-8520
>
> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
> <equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Pramod .D
> *Sent:* Monday, January 12, 2015 7:51 AM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] DHW loads difference
>
>
>
> Hi,
>
>
>
> I have modelled an apartment using eQuest. I have given the same inputs
> (capacities, schedules,etc) in both the models for *DHW* but I am getting
> difference in the results. Can anyone please tell how eQuest calculates DHW
> loads. Why I am getting difference in DHW loads. The images are attached.
>
>
>
> Thanks,
>
> Pramod
>
>
>
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