[Equest-users] 回复：RE: Reply： The problem of minimum equipment efficiency requirement of Ashrae 90.1-2007
Nicholas Caton
ncaton at catonenergy.com
Sun May 24 08:53:23 PDT 2015
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]
*Sent:* Sunday, May 24, 2015 8:26 AM
*To:* Nicholas Caton
*Cc:* 赵永青; Julien Marrec; 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]
*Sent:* Sunday, May 24, 2015 8:39 AM
*To:* 冷面寒枪; Julien Marrec
*Cc:* 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
*Ҥ 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):
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 <zhaoyongqing1987 at qq.com>]
*Sent:* Sunday, May 24, 2015 7:13 AM
*To:* Nicholas Caton; Julien Marrec
*Cc:* 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
503271081 at qq.com
------------------ 原始邮件 ------------------
*发**件人**:* "Nicholas Caton";<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>; "Julien Marrec"<julien.marrec at gmail.com>;
*抄送**:* "equest-users at lists.onebuilding"<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:
[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:
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
*From:* Equest-users [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
*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
503271081 at qq.com
------------------ 原始邮件 ------------------
*发**件人**:* "Julien Marrec";<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>;
*抄送**:* "equest-users at lists.onebuilding"<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> 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>
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
503271081 at qq.com
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