[Equest-users] existing buildings/alterations

Busman, Michael R MBusman at chevron.com
Thu Jul 25 14:22:35 PDT 2013


Dan/Bill/Kent,

I guess I'm fortunate to be in the ESCO business where such esoteric questions don't come up.  When it comes to HVAC and central plant equipment to be replaced, we will determine a likely baseline cooling efficiency based on rated efficiency and account for age and conditions that reduce existing equipment cooling efficiency, such as dirty coils & filters, crumbling fins on air-cooled condensers, scaled condensers, short refrigerant charge, excessive approaches, or air in the condenser of chillers.  Although it's possible (but expensive) to field measure performance of a chiller in the field, it's virtually impossible for DX equipment.  That's where the determination of baseline cooling efficiency is as much art as science.

My best,
Mike Busman


Michael R. Busman, CEM
Lead Project Engineer II
 
Chevron Energy Solutions
A Division of Chevron U.S.A., Inc.
145 S. State College Blvd.
Brea, CA  92821 
Direct  714-671-3561
Fax     714-671-3438
eFax   866-420-0335 (Include my Full Name followed by "CAI:MHTZ" on Cover Sheet)
Mobile 310-387-2083
mbusman at chevron.com



-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Daniel Knapp
Sent: Thursday, July 25, 2013 1:34 PM
To: Bishop, Bill
Cc: equest-users at lists.onebuilding.org; Kent Beason
Subject: Re: [Equest-users] existing buildings/alterations

I guess to follow up the interpretation is as such:

If the existing systems are left in place, the proposed and baseline are modelled identically according to the existing systems.

If the existing systems are *replaced*, the proposed is modelled according to the replacements, and the baseline is modelled according to the 90.1 Appendix G requirements. 

Best,
Dan

-
Daniel Knapp, PhD, P Phys, LEED® AP O+M
danielk at arborus.ca

Arborus Consulting
Energy Strategies for the Built Environment
www.arborus.ca
76 Chamberlain Avenue 
Ottawa, ON, K1S 1V9 
Phone: (613) 234-7178 ext. 113
Fax: (613) 234-0740




On 2013-07-25, at 4:24 PM, "Bishop, Bill" <bbishop at pathfinder-ea.com> wrote:

> Kent,
>  
> The exception to 6.1.1.2 (allowing existing systems to handle the HVAC needs of additions) provides a way to comply with Standard 90.1 without replacing existing systems. But your question is not about 90.1 compliance, it is about Appendix G modeling (presumably for LEED New Construction). Table G3.1 (10.) is clear on the Baseline HVAC system requirements and provides no exception for existing buildings. There may be exceptions if this is for a utility incentive program or some other application other than for a LEED NC model. Otherwise, I am not aware of any CIRs or other interpretations that would allow modeling existing systems in the Baseline.
>  
> ~Bill
>  
> From: Kent Beason [mailto:kbeason at estesmcclure.com] 
> Sent: Thursday, July 25, 2013 4:03 PM
> To: Bishop, Bill; 'Nick Caton'; equest-users at lists.onebuilding.org
> Subject: RE: [Equest-users] existing buildings/alterations
>  
> Bill,
>  
> Okay...I would classify this as one of those nuances that Nick characterized earlier.  It seems strange to me that this would only apply to the envelope, but after all, it is only stipulated in Table G3.1 under Section 5f Building Envelope.
>  
> To complicate the issue though, someone else's response was to use existing HVAC systems.  Normally I would dismiss his response out of hand, but he was a LEED reviewer at one time and is more 90.1 knowledgeable than me currently.  I was about to send this message, sure that I would model baseline per Appendix G, until I thought to look in Section 6.  Does Section 6.1.1.2 provide the adequate Exception to clarify that old HVAC systems must be modeled in the baseline for a renovation/alteration project?  The term "alteration" in the definitions appears to be applicable as an "addition" as shown in this Exception of 6.1.1.2.  However, the verbiage "shall not be required to comply with this standard" implies that it's optional.
>  
> Kent Beason
> -------------------------
> office - 903 581 2291
> cell - 830 609 8904
>  
> From: Bishop, Bill [mailto:bbishop at pathfinder-ea.com] 
> Sent: Thursday, July 25, 2013 1:55 PM
> To: Kent Beason; 'Nick Caton'; equest-users at lists.onebuilding.org
> Subject: RE: [Equest-users] existing buildings/alterations
>  
> Kent,
>  
> I didn't notice your message was only to me. I assumed it would be a matter of seconds before others replied in the negative. The "existing conditions" caveat applies only to the envelope. You must use the Appendix G baseline systems and plants for the LEED Baseline, with the possible exception of the central plant for DES systems as you mention.
>  
> ~Bill
>  
> From: Kent Beason [mailto:kbeason at estesmcclure.com] 
> Sent: Thursday, July 25, 2013 2:49 PM
> To: 'Nick Caton'; Bishop, Bill; equest-users at lists.onebuilding.org
> Subject: RE: [Equest-users] existing buildings/alterations
>  
> Thanks for the feedback.    As I asked Bill offline, and I feel it goes without saying, but never hurts to be thorough :-): this applies to the old HVAC systems too, correct?  Obtaining the old HVAC system info could be a daunting challenge unfortunately.
>  
> I've learned alot about nuances...  One area of this building is storefront (essentially 100%) single pane glass around the whole perimeter!  
>  
> Kent Beason
> -------------------------
> office - 903 581 2291
> cell - 830 609 8904
>  
> From: Nick Caton [mailto:ncaton at smithboucher.com] 
> Sent: Thursday, July 25, 2013 1:32 PM
> To: Bishop, Bill; Kent Beason; equest-users at lists.onebuilding.org
> Subject: RE: [Equest-users] existing buildings/alterations
>  
> Agreed.  Take note there are a couple nuances between what's written in 90.1 and what's required by the LEED reviewership.  I believe they draw a line in the sand where if more than 50% of a project is "retrofit" vs. NC by square footage, then rotations go away.
>  
> I just had 3 LEED projects wrap up at silver/gold where in the initial submission I used thoroughly documented prescriptive baseline envelopes and 4 rotations.  The preliminary review commentary required changing the envelopes to remove the rotations and match reality instead.  The previous reality was (mostly) uninsulated grout filled block walls, single pane windows without film treatments, and zero wall insulation =D!
>  
> As a net result, each of these projects jumped way up in unanticipated modeling credits.  It was a good day. 
>  
> Outside the constraints of LEED, the closer your baseline models can reflect existing realities, the better and more informative the results of your models become for a retrofit analysis.
>  
> Regards,
>  
> ~Nick
>  
> <image001.jpg>
>  
> 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 Bishop, Bill
> Sent: Thursday, July 25, 2013 1:17 PM
> To: Kent Beason; equest-users at lists.onebuilding.org
> Subject: Re: [Equest-users] existing buildings/alterations
>  
> Kent,
>  
> Yes, for existing buildings, use the wall & roof assemblies, glazing properties etc. of the existing building for the Baseline values. Also, you don't have to simulate in four orientations.
>  
> Regards,
> Bill
>  
> William Bishop, PE, BEMP, BEAP, LEED AP | Pathfinder Engineers & Architects LLP
> Senior Energy Engineer
>  
> 134 South Fitzhugh Street                 Rochester, NY 14608
> T: (585) 325-6004 Ext. 114            F: (585) 325-6005
> bbishop at pathfinder-ea.com           www.pathfinder-ea.com
> P   Sustainability - the forest AND the trees. P   
>  
> From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kent Beason
> Sent: Thursday, July 25, 2013 1:09 PM
> To: equest-users at lists.onebuilding.org
> Subject: [Equest-users] existing buildings/alterations
>  
> This question isn't eQuest specific, but deals with 90.1 interpretation.
>  
> For an existing building, with regards to shell alterations, G3.1.5-f says that "the baseline building shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated."  Is this statement as far-reaching as I believe, indicating that U-values, SHGC etc, listed in Tables 5.5 and Appendix A are ignored in a similar way as done in the proposed, since the "baseline" in this case is a real design, rather than a hypothetical baseline?
>  
> Kent Beason
> Estes, McClure & Associates, Inc.
> 3608 West Way
> Tyler, TX 75703
> -------------------------
> office - 903 581 2721
> cell - 830 609 8904
>  
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