[Bldg-sim] fossil hybrid or electric
Robby Oylear
robbyoylear at gmail.com
Wed Aug 29 13:47:35 PDT 2012
Thanks Arpan,
Sorry for the confusion. The interpretation I posted above is a "LEED
Interpretation".
-Robby
On Wed, Aug 29, 2012 at 1:41 PM, Arpan Bakshi <abakshi at yrgxyz.com> wrote:
>
> It is worth noting there is a difference between LEED Interpretations and
> LEED Project Credit Interpretation Rulings, as far as being precedent
> setting.
>
> Further Reading:
> https://www.usgbc.org/ShowFile.aspx?DocumentID=9277
>
>
>
>
> _________________________________________
>
> *Arpan Bakshi *Sustainability Manager
> LEED AP BD+C, ESTIDAMA PQP
>
> *YR&G*
> sustainability consulting, education and analysis
> *
> 161 Bowery - 4th Floor - NY NY 10002
> *
> D 646.704.2880
>
> yrgxyz.com | facebook<http://www.facebook.com/#%21/pages/YRG-sustainability/109166559111721>
> | twitter <http://twitter.com/#%21/YRGxyz>
>
>
>
>
> On Wed, Aug 29, 2012 at 4:29 PM, Robby Oylear <robbyoylear at gmail.com>wrote:
>
>> Maria,
>>
>> LEED CIRs are precedent setting under LEED. Any CIR that gets posted to
>> the CIR database is considered precedent setting. I agree, the group that
>> wrote that CIR was misinterpreting the standard, but without the
>> interpretation that Michael just posted we would've had no real way to
>> argue against it if it came up as a review comment. Moving forward I would
>> proceed as you recommend for Morgan's scenario.
>>
>> Either way it's unfortunate that the baseline exceptions are limited by
>> 20,000 SF of floor area. On a small project you can end up with some very
>> awkward fuel switching scenarios between baseline and proposed. I would
>> appreciate a 20,000 SF OR X% of the total building area, whichever is
>> smaller.
>>
>> -Robby
>>
>>
>> On Wed, Aug 29, 2012 at 1:20 PM, Maria Karpman <
>> maria.karpman at karpmanconsulting.net> wrote:
>>
>>> Thanks for sharing this Michael! ****
>>>
>>> ** **
>>>
>>> Robby, I don’t believe LEED CIRs are precedent-setting. In addition,
>>> many Appendix G models are developed for programs other than LEED (e.g.
>>> incentive programs) where LEED rulings don’t matter. I would use PTHP on a
>>> LEED project for the situation described by Morgan, referencing G3.1.1
>>> exception (a), footnote to Table G3.1.1A, and the ASHRAE interpretation
>>> that Michael brought up. I don’t think CIR meant to change ASHRAE rules, it
>>> just misinterpreted how they apply to this example . For Vinay’s project, I
>>> would use PTAC in the baseline since apartments use both gas and
>>> electricity as heating source, so fall under Fossil/Electric Hybrid
>>> category.****
>>>
>>> ** **
>>>
>>> Maria****
>>>
>>> ** **
>>>
>>> *From:* Robby Oylear [mailto:robbyoylear at gmail.com]
>>> *Sent:* Wednesday, August 29, 2012 3:57 PM
>>> *To:* Rosenberg, Michael I
>>> *Cc:* maria.karpman at karpmanconsulting.net; Vinay Devanathan;
>>> bldg-sim at lists.onebuilding.org
>>>
>>> *Subject:* Re: [Bldg-sim] fossil hybrid or electric****
>>>
>>> ** **
>>>
>>> Interesting. That is obviously the more logical approach, however we
>>> now have two conflicting interpretations. The 90.1 interpretation is more
>>> recent than the LEED CIR. I'm not sure how one would go about challenging
>>> an existing CIR to get it corrected. Does anyone have any experience with
>>> this? ****
>>>
>>> ** **
>>>
>>> Also, the interpretation does not shed any light on a fossil fuel
>>> preheat/DOAS system serving an electric heating system. I would assume
>>> that this system would still be classified as Fossil/Electric hybhrid and
>>> thus compare to a fossil fuel baseline.****
>>>
>>> ** **
>>>
>>> -Robby****
>>>
>>> On Wed, Aug 29, 2012 at 12:33 PM, Rosenberg, Michael I <
>>> michael.rosenberg at pnnl.gov> wrote:****
>>>
>>> The interpretation issued by the ASHRAE Standard 90.1 Committee agrees
>>> with Maria.****
>>>
>>> ****
>>>
>>>
>>> http://www.ashrae.org/File%20Library/docLib/StdsInterpretations/IC-90-1-2007-11.pdf
>>> ****
>>>
>>> ****
>>>
>>> *__________________________*****
>>>
>>> * *****
>>>
>>> *Michael Rosenberg, CEM, LEED AP *****
>>>
>>> Senior Research Scientist****
>>>
>>> ENERGY & ENVIRONMENT DIRECTORATE ****
>>>
>>> ****
>>>
>>> Pacific Northwest National Laboratory ****
>>>
>>> 2032 Todd Street ****
>>>
>>> Eugene, OR 97405 ****
>>>
>>> (541) 844-1960 ****
>>>
>>> michael.rosenberg at pnnl.gov <michael.rosenberg at pnl.gov> ****
>>>
>>> www.pnnl.gov <http://www.pnl.gov/>****
>>>
>>> ****
>>>
>>> ****
>>>
>>> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
>>> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Robby Oylear
>>> *Sent:* Wednesday, August 29, 2012 12:30 PM
>>> *To:* maria.karpman at karpmanconsulting.net; Vinay Devanathan****
>>>
>>>
>>> *Cc:* bldg-sim at lists.onebuilding.org
>>> *Subject:* Re: [Bldg-sim] fossil hybrid or electric****
>>>
>>> ****
>>>
>>> Maria,****
>>>
>>> ****
>>>
>>> I'd have to disagree with you. No where in G3.1.1 exception (a) does it
>>> say that you can ignore non-predominant conditions. In fact, if you read
>>> the CIR I quoted it very clearly states an example where 90% of the
>>> building is electric heat and the other 10% is gas-heat (less than 20,000
>>> SF) and the baseline model is determined to be Fossil/Electric Hybrid.
>>> ****
>>>
>>> ****
>>>
>>> You may be thinking of the footnote to Table G3.1.1A which states "Where
>>> attributes make a building eligible for more than one baseline system type,
>>> use the predominant condition to determine the system type for the entire
>>> building." However, the CIR is counter to this, and since Table G3.1.1A
>>> includes a category for Fossil/Electric Hybrid, your building would only
>>> fall into one category.****
>>>
>>> ****
>>>
>>> Vinany - the CIR addresses that exact scenario and states that gas
>>> furnace-fired DOAS puts you into the Fossil/Electric Hybrid category and
>>> your baseline would be System 1 PTAC with HW.****
>>>
>>> ****
>>>
>>> -Robby****
>>>
>>> On Wed, Aug 29, 2012 at 12:13 PM, Vinay Devanathan <
>>> vinay.devanathan at gmail.com> wrote:****
>>>
>>> What would be the case for a project with residences using Heat Pumps
>>> for conditioning and a gas furnace-fired DOAS for ventilation to residences
>>> and common spaces?****
>>>
>>> ****
>>>
>>> Vinay****
>>>
>>> ****
>>>
>>> On Wed, Aug 29, 2012 at 3:09 PM, Maria Karpman <
>>> maria.karpman at karpmanconsulting.net> wrote:****
>>>
>>> I think that in Morgan’s case using PTHP baseline is also justified.
>>> From what I understand, the project is a residential buildings with
>>> electrically heated living units and gas-heated common spaces. Applying
>>> G3.1.1 to the project, predominant conditions are residential with
>>> electricity as heat source; non-predominant conditions are non-residential
>>> with fossil fuel heat. Based on G3.1.1 exception (a), non-predominant
>>> conditions accounting for less than 20,000 SF may be ignored when selecting
>>> the baseline system from Table G3.1.1A, thus the baseline for the project
>>> is PTHP. If residential units were served by WSHP, then predominant
>>> conditions would be residential with Fossil/Electric Hybrid heating source,
>>> and the baseline system would by PTAC. ****
>>>
>>> ****
>>>
>>> Maria****
>>>
>>> ****
>>>
>>> *From:* bldg-sim-bounces at lists.onebuilding.org
>>> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Robby
>>> Oylear
>>> *Sent:* Wednesday, August 29, 2012 11:14 AM
>>> *To:* Morgan Heater
>>> *Cc:* bldg-sim at lists.onebuilding.org
>>> *Subject:* Re: [Bldg-sim] fossil hybrid or electric****
>>>
>>> ****
>>>
>>> Morgan,****
>>>
>>> ****
>>>
>>> I agree with Bill. I find this LEED CIR (see below) to be helpful in
>>> determining how fossil/electric hybrid systems should be handled. Your
>>> scenario sounds similar to item 5 under the examples of systems that would
>>> be modeled with fossil fuel heating.****
>>>
>>> ****
>>> LEED Interpretations****
>>>
>>> 11/1/2011 *ID#10132*****
>>>
>>> · MPR/Prerequisite/Credit: *EAp2: Minimum Energy Performance****
>>> *
>>>
>>> · Primary Rating System: *Core & Shell v2.0*****
>>>
>>> Email<https://www.usgbc.org/leedinterpretations/LIDetails.aspx?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>
>>> ****
>>> Ruling****
>>>
>>> Clarification is requested regarding when a building heat source in
>>> Table G3.1.1A should be identified as "Fossil/Electric Hybrid" versus
>>> "Electric".
>>>
>>> The ASHRAE 90.1-2007 User's Manual states that a fossil/electric hybrid
>>> source "refers to a system with any combination of fossil and electric
>>> heat, and the baseline system for this is a fossil fuel system". Therefore,
>>> the heating source for the proposed building would be considered "Fossil
>>> Fuel" or "Fossil/Electric Hybrid" if the building uses any fossil fuel
>>> source for space heating (including backup heating or preheating), and the
>>> baseline building heat source would be fossil fuel.
>>>
>>> Exception: ASHRAE 90.1 Section G3.1.1 Exception (a) stipulates
>>> additional system type(s) for non-predominant conditions (i.e.
>>> residential/non-residential or heating source) if those conditions apply to
>>> more than 20,000 square feet of conditioned floor area.
>>>
>>> EXAMPLES OF BASELINE HEATING SOURCE DETERMINATION:
>>>
>>> The Baseline heat source from Table G3.1.1A for the following Proposed
>>> Case system types would be fossil fuel since the proposed system design
>>> includes a combination of fossil and electric heat:
>>>
>>> 1. Variable air volume system with gas furnace preheat and electric
>>> reheat
>>> 2. Packaged terminal heat pumps with outside air tempered by fossil fuel
>>> furnace
>>> 3. Water source heat pumps with fossil fuel boiler
>>> 4. Ground source heat pumps with backup fossil fuel boiler
>>> 5. 90,000 square feet is conditioned by a variable air volume system
>>> with electric reheat, and 10,000 square feet is conditioned with fossil
>>> fuel furnaces
>>>
>>> The following buildings would be modeled with an additional system type
>>> with a different Baseline heating source in accordance with Section G3.1.1
>>> Exception (a):
>>>
>>> 1. 90,000 square feet is conditioned by a variable air volume system
>>> with electric reheat, and 20,000 square feet is conditioned with Packaged
>>> DX systems with fossil fuel furnaces. In this case, the 90,000 square feet
>>> of area would be modeled with an electric heat source in the Baseline Case
>>> (System Type #6 - Packaged VAV with Electric PFP Boxes), and the 20,000
>>> square feet of area would be modeled with a fossil fuel heat source in the
>>> Baseline Case (System Type #3 - Packaged Single Zone AC with fossil fuel
>>> furnace).
>>> 2. 50,000 square feet is conditioned by water source heat pumps with a
>>> fossil fuel boiler, and 25,000 square feet is conditioned by electric heat
>>> pumps. In this case, the 50,000 square feet of area would be modeled with a
>>> fossil fuel heat source in the Baseline Case (System Type #5 - Packaged VAV
>>> with hot water reheat), and the 25,000 square feet of area would be modeled
>>> with an electric heat source in the Baseline Case (System Type #4 -
>>> Packaged Single Zone Heat Pump).
>>>
>>> Applicable Internationally.****
>>> Formal Inquiry****
>>>
>>> Table G3.1.1A lists two possible categories for the building heating
>>> source:
>>> (1) Fossil fuel, fossil/electric hybrid, & purchased heat;
>>> (2) Electric and other.
>>>
>>> In cases where the proposed building design includes both a natural gas
>>> heating source and an electric heating source, when should the heat source
>>> in Table G3.1.1A be identified as "Fossil/Electric Hybrid" versus
>>> "Electric"?****
>>>
>>> Robby Oylear, PE, LEED AP****
>>>
>>> *Mechanical Engineer*****
>>>
>>> *Senior Energy Analyst*****
>>>
>>> * *****
>>>
>>> *D* 206-788-4571****
>>>
>>> *www.rushingco.com* <http://www.rushingco.com/>****
>>>
>>> ****
>>>
>>> On Tue, Aug 28, 2012 at 5:41 PM, Bishop, Bill <bbishop at pathfinder-ea.com>
>>> wrote:****
>>>
>>> Morgan,****
>>>
>>> ****
>>>
>>> My vote is for PTAC with hot-water boiler.****
>>>
>>> ****
>>>
>>> Regards,****
>>>
>>> Bill****
>>>
>>> ****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
>>> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Morgan Heater<wbishop at pathfinder-ea.com>
>>> ****
>>>
>>>
>>> *Sent:* Tuesday, August 28, 2012 8:12 PM
>>> *To:* bldg-sim at lists.onebuilding.org
>>> *Subject:* [Bldg-sim] fossil hybrid or electric<wbishop at pathfinder-ea.com>
>>> ****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> Hi – I’ve got an appendix G baseline system question. Here’s the
>>> scenario, let me know what you think. <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> Proposed Building: <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> 1. Multi-family residential, amenity/common space < 20,000 square
>>> feet <wbishop at pathfinder-ea.com>****
>>>
>>> 2. Electric baseboard heat in the units<wbishop at pathfinder-ea.com>
>>> ****
>>>
>>> 3. Condensing gas furnaces in the corridors and back of house
>>> spaces <wbishop at pathfinder-ea.com>****
>>>
>>> 4. VRF in amenity common spaces <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> My understanding is that because my non-predominant condition
>>> (common/amenity space) is less than 20,000 square feet, I use a single
>>> system for the whole baseline building (G3.1.1a). I’ve got a mix of gas
>>> and electric heat in the baseline building, does this mean that my base
>>> system is PTAC with a hot water boiler? <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> Thanks! <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>> Morgan Heater, P.E. <wbishop at pathfinder-ea.com>****
>>>
>>> BEMP, LEED AP <wbishop at pathfinder-ea.com>****
>>>
>>> morgan at ecotope.com <wbishop at pathfinder-ea.com>****
>>>
>>> 206-322-3753 ext 209 <wbishop at pathfinder-ea.com>****
>>>
>>> <wbishop at pathfinder-ea.com>****
>>>
>>>
>>> _______________________________________________
>>> Bldg-sim mailing list
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>>> To unsubscribe from this mailing list send a blank message to
>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG <wbishop at pathfinder-ea.com>****
>>>
>>> **** <wbishop at pathfinder-ea.com>
>>> ------------------------------
>>> <wbishop at pathfinder-ea.com>
>>>
>>> ** **
>>>
>>> ****
>>>
>>> ****
>>>
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
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>>> ****
>>>
>>>
>>> _______________________________________________
>>> Bldg-sim mailing list
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>>> To unsubscribe from this mailing list send a blank message to
>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG****
>>>
>>>
>>>
>>> ****
>>>
>>> ****
>>>
>>> -- ****
>>>
>>> Vinay Dev****
>>>
>>>
>>>
>>> _______________________________________________
>>> Bldg-sim mailing list
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>>> To unsubscribe from this mailing list send a blank message to
>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG****
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>>> ****
>>>
>>> ** **
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>>> ****
>>>
>>
>>
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