[Equest-users] LEED Issue with EQuest Software's Ability toModelBoilers on Ground Loops

[Paul Diglio]

Kathryn:

You can add Process/DHW loads to your WLHP as Mbtu/h.  The schedule needs to be a fraction so you can't maintain a certain loop temperature, just a fraction of the Mbut/h per hour based on time of year..  I did one project where I need to add heat to the loop and I wrote a summer/winter schedule.  The boiler/Process Load was off during the summer and I adjusted the winter fractions to eliminate loop errors.

This job was in Boston.  I ended up with a summer schedule starting April 15 (no aux heat) until December 31, when the fractional schedule kicked in until April 14.


 
Paul Diglio


87 Fairmont Avenue
New Haven, CT  06513
203-415-0082


________________________________
 From: Kathryn Kerns <kathryn.kerns at bceengineers.com>
To: James Hansen <JHANSEN at ghtltd.com>; Nick Caton <ncaton at smithboucher.com>; Steve Woolery <steve.woolery at bceengineers.com>; equest-users at lists.onebuilding.org 
Sent: Thursday, August 15, 2013 3:20 PM
Subject: Re: [Equest-users] LEED Issue with EQuest Software's Ability toModelBoilers on Ground Loops
 


 
James and Nick and everyone, 
 
I have already explained to LEED that the proposed energy model has no error messages, no unmet hour issues and showed them the BEPS and PV-A reports. 
 
Maybe if I printed out all the other PV reports that show the ground loop and ground pump part load performance and point out that the ground loop never reaches 100% part load and the pump only reaches 100% part load for 1 hour? Maybe I could generate the custom report for the ground loop temperatures and attach all this information to the exceptional calculation block? 
 
The problem is, I am not sure adding more reports fits with their demand for either a modeled boiler or an exceptional calculation.
 
So back to the first question- does anyone know how to attach a boiler to a HP Water Loop that also has a ground loop HX and run the model successfully?
________________________________
 From: James Hansen [mailto:JHANSEN at ghtltd.com]
Sent: Thu 8/15/2013 11:57 AM
To: Kathryn Kerns; Nick Caton; Steve Woolery; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] LEED Issue with EQuest Software's Ability toModelBoilers on Ground Loops


Sorry, I assumed since you could add a boiler to a WSHP loop that you could run it too :)
 
Indeed there is an error when processing.
 
You could always add the boiler load as a process load (in order to get unmet load hours down).
 
However, you don't have an issue with unmet load hours right?  If there is a boiler that shows up in your proposed design (ie contract documents) that is there for backup, but your hourly reports show that you don't need one, just submit hourly reports and explain this.
 
GHT Limited
James Hansen, P.E., LEED AP
Senior Associate
1010 N. Glebe Road, Suite 200
Arlington, VA  22201-4749
703-243-1200 (office)
703-338-5754 (cell)
703-276-1376 (fax)
www.ghtltd.com
 
From:Kathryn Kerns [mailto:kathryn.kerns at bceengineers.com] 
Sent: Thursday, August 15, 2013 2:45 PM
To: Nick Caton; James Hansen; Steve Woolery; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] LEED Issue with EQuest Software's Ability toModelBoilers on Ground Loops
 
Nick if you have some way of adding a boiler to the HP Water Loop containing the Ground Loop HX without getting the "cannot combine a boiler  and a ground loop HX" fatal error, please show me. I must be missing something.
 

________________________________
 
From:Nick Caton [mailto:ncaton at smithboucher.com]
Sent: Thu 8/15/2013 10:59 AM
To: James Hansen; Kathryn Kerns; Steve Woolery; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] LEED Issue with EQuest Software's Ability toModelBoilers on Ground Loops
If it were me, I’d just add the inconsequential boiler, state/show I did so, and move on.  Typically less effort than building an impenetrable case to someone being contrarian.
 
To bullet #3:  I think not for the standard output reports, but loop entering and exiting temperatures are options in the custom hourly output report dialog, which I believe you can assign to any loop type.  This will put out a CSV you can use with a spreadsheet software of your choosing to quickly come up with minimums/maximums over the simulation.  
 
Attached is a past thread with a spelled out / illustrated procedure for setting up a custom hourly report, in case that’s helpful.
 
Best regards,
 
~Nick
 
 
NICK CATON, P.E.
SENIOR ENGINEER
 
Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com
 
From:equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of James Hansen
Sent: Thursday, August 15, 2013 11:36 AM
To: Kathryn Kerns; Steve Woolery; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] LEED Issue with EQuest Software's Ability to ModelBoilers on Ground Loops
 
You can absolutely add a boiler to a GSHP loop.  Just add a boiler, and when asked which HW loop to assign it to, you can pick the GSHP Loop (as long as that loop is a "Water Loop HP" loop).
 
I think more than likely this is the reason you are getting the comments you are.  This reviewer may know that you CAN add a boiler to a GSHP loop, which is the reason for comment #4.
 
I doubt GBCI is trying to eliminate eQuest as a modeling option.
 
Also, printing out hourly reports from an eQuest run is often helpful in proving your case (whatever case that may be).  If you can show, via hourly reports, that the heat picked up by the GSHP heat exchanger exceeds the heating load for all 8,760 hours of the day, then case closed...that's all you need to submit.
 
GHT Limited
James Hansen, P.E., LEED AP
Senior Associate
1010 N. Glebe Road, Suite 200
Arlington, VA  22201-4749
703-243-1200 (office)
703-338-5754 (cell)
703-276-1376 (fax)
www.ghtltd.com
 
From:equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kathryn Kerns
Sent: Thursday, August 15, 2013 12:27 PM
To: Steve Woolery; equest-users at lists.onebuilding.org
Subject: [Equest-users] LEED Issue with EQuest Software's Ability to ModelBoilers on Ground Loops
 
Everyone, I have received a snarky comment from the LEED reviewers regarding eQuest and not being able to model back-up boilers on a ground heat pump loop. See below. The ground loop is large enough not to generate any temperature low alarm messages, the ground loop pump flow never reaches 100% flow except for 1 hour and the ground loop heating capacity is never exceeded. These facts do not appear to be a good enough explanation not modeling the back up gas boiler. 
 
My questions for the group are:
1. Is there a way to add a boiler or some additional heat source to a ground loop in eQuest?  As far as I know the only work around I have discovered is to represent the ground loop by creating a water loop and adding a magical no energy consuming boiler and fluid cooler to a heat pump water loop and change the water loop parameters to match ground loop parameters. Then you can add normal boilers that will start if the non-energy consuming ground loop boiler is too small for the building heat load.  I offered this option to the LEED reviewer and they replied that it was not an established work around.
 
2. If there is no way to attach a boiler to a ground loop in eQuest, is there some established work around that somebody has used that was accepted by a LEED reviewer?
 
3. Is there anything in the reports that lists the maximum and minimum ground loop temperatures? I have been unable to locate it. 
 
4. Does anyone have an written explanation to answer "If this [the boiler] is not being modeled in the energy modeling software then provide a thorough explanation for why it cannot be modeled. "?
 
5. Does this sound like LEED is trying to eliminate eQuest software, and if so, is there anything we can do about it? "in the future the software selected to simulate the building components must be able to model those components "
 
The project team could possibly demonstrate that the boiler would not operate through a series of engineering calculations, some other software that could possibly simulate the building’s loop temperatures, or through a thorough explanation of how the system operation prevents the boiler from operating. In short the project team must demonstrate that the boiler will not operate, not just say that is the case without presenting some evidence. If this is not being modeled in the energy modeling software then provide a thorough explanation for why it cannot be modeled. In the future the software selected to simulate the building components must be able to model those components or use an exceptional calculation (work around) to do so (G2.2). 
 

________________________________
 
_______________________________________________
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/20130815/1772d5cd/attachment-0002.htm>