[Equest-users] ： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Jones, Christopher
cjones at halsall.com
Mon May 25 06:41:27 PDT 2015
I think the reviewer is daft. The efficiencies listed in Section 6 are the prescriptive requirements that the baseline model is to employ. There is nothing in Section 6 or Appendix G stating that the average seasonal efficiency of a boiler is to be equal to its full load efficiency. Unless there is a recent CIR from the USGBC then the reviewer needs to go back to school.
Christopher Jones, P.Eng.
Tel: 416.644.4226 • Toll Free: 1.888.425.7255 x 527
From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Nicholas Caton
Sent: Sunday, May 24, 2015 11:53 AM
To: 冷面寒枪; Julien Marrec
Cc: equest-users at lists.onebuilding
Subject: Re: [Equest-users] 回复：RE: Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Yeah the divergence in PS-C output results from the nominal HIR input are definitely a combination of cycling energies and the library curve being “non-flat.” The specific direction to prescribe part load performance by modifying the curve is what’s really irking me here (and the notion/implication that every other boiler using library curves & default warmup/standby inputs is wrong for LEED).
In any case, I do appreciate the suggestion – when I get around to addressing that model’s commentary I will check up on whether the baseline boilers are oversized and will plan to include that review in addressing the comment. That would definitely be contributing to the “problem” if it were the case!
~Nick
NICK CATON, P.E.
Owner
Caton Energy Consulting
1150 N. 192nd St., #4-202
Shoreline, WA 98133
office: 785.410.3317
www.catonenergy.com
From: David Eldridge [mailto:DEldridge at grummanbutkus.com<mailto:DEldridge at grummanbutkus.com>]
Sent: Sunday, May 24, 2015 8:26 AM
To: Nicholas Caton
Cc: 赵永青; Julien Marrec; equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>
Subject: Re: [Equest-users] Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
The referenced 90.1 method of testing for boiler efficiency should be the guide. The value is not presented as an "IPLV" type of weighted efficiency.
The reviewer might have a question if your baseline boiler is cycling a lot, did the Appendix G sizing instructions provide an oversized boiler?
DSE Mobile
From: Nicholas Caton [mailto:ncaton at catonenergy.com<mailto:ncaton at catonenergy.com>]
Sent: Sunday, May 24, 2015 8:39 AM
To: 冷面寒枪; Julien Marrec
Cc: equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>
Subject: RE: 回复：RE: [Equest-users] Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
I’m happy you are arriving at the same result, however to be clear I do not think the reviewer is correct to assert the prescribed efficiency is anything other than the full-load efficiency.
Follow the cited Test Procedure CFR 431 led me to:
https://www.law.cornell.edu/cfr/text/10/431.86
“§ 431.86 (c) (3) (ii) Thermal Efficiency. Use the calculation procedure for the thermal efficiency test specified in Section 11.1 of the HI BTS-2000, Rev 06.07 (incorporated by reference, see§ 431.85).”
I then found the referenced HI standard here (PDF link): https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAA&url=https%3A%2F%2Flaw.resource.org%2Fpub%2Fus%2Fcfr%2Fibr%2F004%2Fhi.BTS-2000.2007.pdf&ei=R-dhVZr3FoffoASKxYC4Bw&usg=AFQjCNGb2HahzcO_Q-BftBzCugY5sPtifg&sig2=k1fojL9GcpjnN6T2fdzOug
In that standard, section 5 reads:
5.0 TYPES OF TESTS
5.1 Thermal Efficiency Test
Shall consist of a test point conducted at 100% ± 2% of the nameplate boiler input. The test shall
yield a complete accounting of the energy input in terms of output and losses.
5.2 Combustion Efficiency Test
Shall consist of a test point conducted at 100% ± 2% of the input to the boiler and shall yield an
accounting of energy input in terms of products of combustion only.
From this, it is clear Et and Ec as prescribed by 90.1 are only the efficiencies as measured at full load. The test procedures following under section 9 deliberately exclude the effects of warmup/standby (equipment is made to warm up and arrive at the mandated operating conditions prior to measurements).
Section 11.1 of the standard prescribes all the calculations required, including Et = 100*QOUT / QIN , however the preceding sections makes clear we are in no way standardizing part load performance or warmup/standby performance.
Rounding back to 90.1… section 6.4.1.1 further cements the notion (“packaged boilers” fall under 1992 EPACT):
[cid:image001.png at 01D096CE.F8117F30]
All this reinforces the point that 90.1 simply does not prescribe part load performance for baseline boilers. To perform a simulation in compliance with Appendix G the onus is upon the energy modeler to make reasonable, defensible assumptions on that front. I don’t see how forcing full-load efficiencies at all part-load conditions and removing standby/startup operation energies is more reasonable or reflects reality better than the defaults.
If this is a new GBCI position they plan to hard-line on, then I would speculate it would be equally fair (albeit far more unrealistic for condensing cases) to give your proposed boilers the same treatment… extra work for a step backwards from reality…?
Thoughts?
~Nick
NICK CATON, P.E.
Owner
Caton Energy Consulting
1150 N. 192nd St., #4-202
Shoreline, WA 98133
office: 785.410.3317
www.catonenergy.com
From: 冷面寒枪 [mailto:zhaoyongqing1987 at qq.com]
Sent: Sunday, May 24, 2015 7:13 AM
To: Nicholas Caton; Julien Marrec
Cc: equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>
Subject: 回复：RE: [Equest-users] Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Hi,Nick
Than you for your insight!
Except default curve and start up time, Min-Ratio also will result in discrepancy between annual equivalent HIR and nominal HIR. After I revised curve ,set start-time and Min-Ratio to 0,and hourly report and PS-C report indicate that the annual equivalent HIR is accord with nominal HIR
------------------
Yongqing Zhao
Changsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan,China
Telephone:13574805636
Email:zhaoyongqing1987 at 126.com<mailto:Email%3Azhaoyongqing1987 at 126.com>
503271081 at qq.com<mailto:503271081 at qq.com>
------------------ 原始邮件 ------------------
发件人: "Nicholas Caton";<ncaton at catonenergy.com<mailto:ncaton at catonenergy.com>>;
发送时间: 2015年5月24日(星期天) 晚上9:53
收件人: "赵永青"<503271081 at qq.com<mailto:503271081 at qq.com>>; "Julien Marrec"<julien.marrec at gmail.com<mailto:julien.marrec at gmail.com>>;
抄送: "equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>"<equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>>;
主题: RE: [Equest-users] Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
I received some similar review language very recently suggesting 80% efficiency is expected at all/most part load conditions for the baseline boiler…. Similar context in that case with the boiler rarely operating near full load.
My comment has other issues that would cloud the topic at-hand, but here is truncated version:
“…Furthermore, the average boiler efficiencies in the Baseline PS-C output reports, calculated by dividing the boiler energy consumption by the annual boiler heating energy generated was… [approximately 5% lower than the nominal efficiency input & documented]. Revise the baseline boiler efficiency to 80% and revise the boiler curve for the Baseline case as necessary to have an average efficiency that is near 80%. Provide updated PS-C reports for the Baseline confirming that the average baseline efficiency is near 80%.”
This is the first time I have run into commentary checking up on PS-C’s output at all, and I’m using the same library curves as always for typical baseline boilers.
I believe the PS-C discrepancy is explained both by the non-flat library curve and by the boiler’s default start-up loads, in combination.
Here is the default library curve – it is (roughly, but not quite) linear:
[cid:image002.png at 01D096CE.F8117F30]
[cid:image003.png at 01D096CE.F8117F30]
[For those unfamiliar, the Y-axis is a unitless multiplier]
If I’m not mistaken, this curve serves double-duty: it simultaneously applies the hourly PLR to the full capacity (as either input or auto-sized) and also accounts for increased HIR (lower efficiency) as the PLR drops. My understanding in equation form:
Energy Consumed (for the hour) = (Boiler full capacity as input/autosized) * (Boiler nominal HIR input @ full load) * HIRf(PLR)
If all of that is true, a perfectly “flat efficiency” curve, returning your nominal input HIR at all efficiencies, would therefore be Z = X. That’s plotted above for reference with a light/thin line.
Even with such a “flat efficiency” curve applied to a test-case, PS-C’s outputs still suggest an annual equivalent HIR higher than the nominal input. Zeroing out the startup/standby inputs as well is required to get PS-C to report your nominal HIR = annual fuel / annual load:
[cid:image004.png at 01D096CE.F8117F30]
I think the correct response (which perhaps I’ve mostly composed above) is to demonstrate the causes (library curve shape, startup/standby defaults), and to assert these are all appropriately applied to the baseline boiler, though none of this is regulated by 90.1 to the best of my knowledge so it might be relatively shaky territory.
I would wager 90% of all eQuest baseline boilers submitted to GBCI to date probably don’t mess with the library curves or standby/startup inputs, but that’s pure speculation on my part.
Has anybody ever tried to explain/justify the default boiler curve and default startup/standby inputs? Do we know where those defaults come from?
~Nick
NICK CATON, P.E.
Owner
Caton Energy Consulting
1150 N. 192nd St., #4-202
Shoreline, WA 98133
office: 785.410.3317
www.catonenergy.com<http://www.catonenergy.com>
From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org>] On Behalf Of ???
Sent: Sunday, May 24, 2015 5:34 AM
To: Julien Marrec
Cc: equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>
Subject: [Equest-users] Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Hi,Julien
I understand his meaning is keep a constant efficiency and I know the flat efficiency in equest is a curve that is y=x, but I can't confirm if a constant efficiency is Ashrae 90.1-2007's original intent.
------------------
Yongqing Zhao
Changsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan,China
Telephone:13574805636
Email:zhaoyongqing1987 at 126.com<mailto:Email%3Azhaoyongqing1987 at 126.com>
503271081 at qq.com<mailto:503271081 at qq.com>
------------------ 原始邮件 ------------------
发件人: "Julien Marrec";<julien.marrec at gmail.com<mailto:julien.marrec at gmail.com>>;
发送时间: 2015年5月24日(星期天) 晚上8:19
收件人: "赵永青"<503271081 at qq.com<mailto:503271081 at qq.com>>;
抄送: "equest-users at lists.onebuilding<mailto:equest-users at lists.onebuilding>"<equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>>;
主题: Re: [Equest-users] The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Hey,
He's saying that you need to make sure that the curve boiler-fPLR gives you a constant efficiency. As far as I remember, the default atmospheric curve from equest is like this.
Don't be confused by "flat". A flat efficiency curve is when you plot efficiency=f(PLR). In equest, it should be a curve that is y=x
Look at the curve you used.
Best,
Julien
Envoyé de mon iPhone
Le 24 mai 2015 à 11:27, "赵永青" <503271081 at qq.com<mailto:503271081 at qq.com>> a écrit :
I get the energy model comments from LEED reviewer as following:
The narrative response indicates that the Baseline boiler has been modeled utilizing operating performance curves and a boiler HIR of 1.25. However, since the boiler operation HIR is based on the performance curves, the HIR is less than 1.25 in the part-load condition, which is inappropriate. Revise the Baseline boilers to include a flat efficiency of 80% for all part-loads. Provide eQuest input files or screen shots verifying the boiler efficiency has been modeled as required.
<545E22AD at FA528147.9F996155<mailto:545E22AD at FA528147.9F996155>>
However, I can not understand it very much. The minimum equipment efficiency requirement(80 % Et) of Ashrae 90.1-2007 should be base on full load condition.Why the LEED reviewer raise such a question?Any insight is appreciate!!
Thanks
------------------
Yongqing Zhao
Changsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan,China
Telephone:13574805636
Email:zhaoyongqing1987 at 126.com<http://126.com>
503271081 at qq.com<mailto:503271081 at qq.com>
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