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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I deal with unmet hours by supplying more
air rather than upsizing capacity, and it has worked.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 color=navy face="Times New Roman"><span
style='font-size:10.0pt;color:navy'>Jorge E. Torres Coto </span></font><font
size=1 color=black><span style='font-size:1.0pt;color:black;border:none windowtext 1.0pt;
padding:0in;background:black;layout-grid-mode:line'> </span></font><font
size=2 color=navy><span style='font-size:10.0pt;color:navy'><img width=39
height=39 id="_x0000_i1027" src="cid:image002.jpg@01CB89AB.99FA1EF0"><o:p></o:p></span></font></p>
<p class=MsoNormal><st1:Street w:st="on"><st1:address w:st="on"><font size=2
color=navy face="Times New Roman"><span style='font-size:10.0pt;color:navy'>4830
Viewridge Ave.</span></font></st1:address></st1:Street><font size=2
color=navy><span style='font-size:10.0pt;color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Times New Roman"><span
lang=ES-MX style='font-size:10.0pt;color:navy'>San Diego, CA 92123<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Times New Roman"><span
lang=ES-MX style='font-size:10.0pt;color:navy'>p 858.751.0933<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Times New Roman"><span
lang=ES-MX style='font-size:10.0pt;color:navy'>f 858.751.0937<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Times New Roman"><span
style='font-size:10.0pt;color:navy'>c 858.688.6088<o:p></o:p></span></font></p>
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style='font-size:12.0pt;color:navy'><img width=181 height=159 id="_x0000_i1028"
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<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
bldg-sim-bounces@lists.onebuilding.org
[mailto:bldg-sim-bounces@lists.onebuilding.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Carol Gardner<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, November 19, 2010
4:48 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Nick Caton<br>
<b><span style='font-weight:bold'>Cc:</span></b>
bldg-sim@lists.onebuilding.org; Michael Collarin<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Bldg-sim] Adjusting
Capacity for Unmet Cooling</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Hi All,<br>
<br>
I think Nick is spot on in his discussion re unmet hours. While I'm not saying
it's a wrong thing to do, I personally have never used oversizing the system as
a way to get rid of unmet hours.<br>
<br>
As an example, I have been helping someone off the list with his project, a
seemingly very simple building with only 5 thermal zones and one PVAVS air
handler with dx cooling and hot water heating - system 5. After running my 4
exposures, and having none of them with <b><span style='font-weight:bold'>any</span></b>
hours of unmet loads, I calculated my kW/cfm, heating load, cooling load,
boiler kW and all of that, put the calculated results in the baseline, reran
the baseline, and for some darn reason I had over 1000 hours of unmet cooling
loads.<br>
<br>
I checked all my inputs, made a few changes, reran the 4 exposures, and not
much changed. So, I put on my thinking cap and read Nick's email - not necessarily
in that order. One of the things that occurred to me is that since the building
is turned off all weekend my Monday morning pull down loads during the summer
might be the cause of the problem, so I put in an optimum start schedule (this
might have been required, I haven't double checked) and my unmet hours were
reduced by about 300 hours. I had an adequate cfm/sf, something I'm not shy
about raising at all since eQUEST defaults it to 0.5 cfm/sf which is usually
too small, so I didn't change it. Then I looked at the throttling-range. <br>
<br>
For VAV systems the eQUEST/DOE2 manuals say that the throttling range should be
<b><span style='font-weight:bold'>at least</span></b> 4 degrees to insure
stable operation and that is what I had it at originally. After thinking about
it and doing some simple math in my head I raised it to 6 degrees. My cooling
temperature is set at 75 degrees so this means when my room temperature reads
79, set point temp + 1/2 TR + 1 degree, my cooling coils will be activated.
Before I did this I had also looked at my SS-F reports and could see that my
room temps weren't that far off from the set point temp when I had under cooled
hours reported. Using the new throttling range brought me down to less than 500
hours of unmet loads, which may work.<br>
<br>
So this is an example of the thinking around what's going on and developing a
strategy that makes sense for a specific building. I also looked at my
heating/cooling temp schedules, etc., as Nick mentioned. What baffles me is
why, after none of my 4 exposures showed any unmet load hours, my baseline did.
I, like Nick, have not had that happen before. Perhaps it has something to do
with the way the building was zoned, 4 exposures and a core but I don't know
for sure.<br>
<br>
Any ideas?<br>
<br>
<br>
Carol<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Fri, Nov 19, 2010 at 2:56 PM, Nick Caton <<a
href="mailto:ncaton@smithboucher.com">ncaton@smithboucher.com</a>> wrote:<o:p></o:p></span></font></p>
<div bgcolor=white link=blue vlink=purple>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Hi Michael,</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>I’d like to offer a quick heads up – your interpretation of what
90.1 has to say regarding addressing unmet hours is spot on and well-stated, no
disagreements here. Neeraj however is indirectly making a pretty valid
point that I’d hate for anyone to miss…</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>If you only ever approach addressing unmet hours by bumping the
oversizing factors, you may well be missing something critical. I for one
was in this train of thought when I started out. To the letter of the
standard, indeed this is all we’re *prescribed* to do to remedy the situation,
but this approach will not always work, and may result in baseline models with
a very skewed performance – suffice it to say skewed is not always a *good*
thing, even if it does make your performance numbers look good.</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Whenever I have unmet hours, I’ve learned through others on
these lists to investigate the “why” and “when” of those unmet hours as a first
step. More often than not, unmet hours in my models, when they do occur,
have nothing to do with lacking heating or cooling capacity – fan (airflow)
scheduling conflicts, thermostat setpoints and unrealistic deadbands are the
primary culprits. The systems effectively aren’t running as frequently or
for a duration as they should be.</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>When this is the case, and I can assure Neeraj is not alone in
this experience, fluffing the oversizing factor may appear to “remedy” the
issue, but often as not may *not* be enough to pull your
baseline/proposed models into the prescribed requirements for unmet
hours. In some cases, you might even make the situation worse. I’m
pretty sure the spirit of the standard, by specifying a maximum number of unmet
hours, is to allow both the proposed and baseline systems to run when they need
to satisfy the loads</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>For whatever combination of reasons, and luck may be a part of
it, it has been a long while since I’ve created an autosizing 90.1 baseline
model whose unmet hours did not ring in at either zero or the single digits,
and as such did not require any adjustments. I personally feel this has
had a lot to do with understanding the mechanics behind what defines and can
cause an unmet hour – as you’re getting at with consideration to drift points.
</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>As you say, future versions of 90.1 may be more nuanced, but I
personally feel the manner in which unmet hours are currently addressed does a
disservice to those aspiring to be quality energy modelers – one can easily be
misled to believe an unmet load hour is a problem in and of itself with an easy
“fix,” without recognizing it’s really a symptom of a problem... bumping
capacities without first addressing the cause of unmet hours is something like
a doctor only giving you a band-aid for a cut when what you need is a tetanus
shot!</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>It may be worth mentioning that my experience is dominantly
within the world of eQuest/DOE2. I would not be surprised to find
other engines/software have varying “typical” causes of unmet hours.</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Anyway, that’s my two cents, for what it’s worth =) – hope it
might help lead others along the path!</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>~Nick</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'><img border=0 width=119 height=37 id="_x0000_i1025"
src="cid:image004.jpg@01CB89AB.99FA1EF0" alt="cid:489575314@22072009-0ABB"></span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><font
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size=2 color="#2d4d5e" face="Times New Roman"><span style='font-size:11.0pt;
color:#2D4D5E;font-weight:bold'>NICK CATON, E.I.T.</span></font></b><o:p></o:p></p>
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size=1 color="#cc9900" face="Times New Roman"><span style='font-size:7.5pt;
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color:#2D4D5E'>25501 west valley parkway</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><st1:City
w:st="on"><st1:place w:st="on"><font size=2 color="#2d4d5e"
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size=2 color="#2d4d5e"><span style='font-size:10.0pt;color:#2D4D5E'> ks 66061</span></font><o:p></o:p></p>
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color:#2D4D5E'>fax 913 345.0617</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><i><font
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title="blocked::www.smithboucher.com"><font size=2><span style='font-size:10.0pt'>www.smithboucher.com</span></font></a></span></font><u><font
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<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;
border-color:-moz-use-text-color -moz-use-text-color'>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><font
size=2 face="Times New Roman"><span style='font-size:10.0pt;font-weight:bold'>From:</span></font></b><font
size=2><span style='font-size:10.0pt'> <a
href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>]
<b><span style='font-weight:bold'>On Behalf Of </span></b>Michael Collarin<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, November 19, 2010
1:46 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Nearedge; <a
href="mailto:cjaigath@yahoo.com" target="_blank">cjaigath@yahoo.com</a><o:p></o:p></span></font></p>
<div>
<div>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'><br>
<b><span style='font-weight:bold'>Cc:</span></b> <a
href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Bldg-sim] Adjusting
Capacity for Unmet Cooling<o:p></o:p></span></font></p>
</div>
</div>
</div>
</div>
<div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Neeraj, it is in fact the contrary. </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>ASHRAE 90.1-2007 Appendix G requires you to model Baseline
Airflow Rate using a 20-degree F temperature difference between the supply air
and room air temperatures. Therefore, if your room set point is 75F for
cooling, set your cooling leaving air temperature to 55F and vice versa for
heating; 72F heating set point requires a 92F leaving air temperature. This
establishes your CFM airflow within the model. Do not vary these to adjust
unmet hours.</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>If you have unmet heating or cooling hours (over 300 or greater
than 50 between baseline and proposed), you may incrementally adjust the
baseline cooling and heating capacities (originally oversized 15% and 25%
respectively) accordingly to reduce the overall unmet hours (below 300) or the
difference between baseline and proposed (within 50).</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Before taking this step, be sure to look at your thermostat
drift points. If the cooling set point is 75, but the cooling drift point is
84, when the space is unoccupied this would allow the space to move toward 84
degrees. When the space becomes occupied and the simulation tries to cool to
75, the system will not be able to achieve this within the allotted time (1
hour) and you will have an unmet cooling hour. </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>There are some changes to ASHRAE 90.1-2010 that will effect
unmet hours, but for the time being, if you are modeling a project using 2007
or 2004, this method should help you eliminate the unmet hours.</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'>Regards,</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><font
size=1 face="Times New Roman"><span style='font-size:8.0pt;font-weight:bold'>Michael
M. Collarin, EIT, LEED AP BD+C </span></font></b><b><font size=1 color=green><span
style='font-size:7.0pt;color:green;font-weight:bold'>| Elm Engineering, Inc. | <st1:Street
w:st="on"><st1:address w:st="on">212 S Tryon St</st1:address></st1:Street> | <st1:address
w:st="on"><st1:Street w:st="on">Suite</st1:Street> 1375</st1:address> | <st1:place
w:st="on"><st1:City w:st="on">Charlotte</st1:City>, <st1:State w:st="on">NC</st1:State>
<st1:PostalCode w:st="on">28281</st1:PostalCode></st1:place></span></font></b><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=1 color=green face="Times New Roman"><span style='font-size:8.0pt;
color:green;letter-spacing:.9pt'>PHONE 704-335-0396 Ext. 108</span></font><font
size=1 color=green><span style='font-size:8.0pt;color:green'>|<b><span
style='font-weight:bold'> </span></b>FAX 704-335-0399<b><span style='font-weight:
bold'> </span></b>|</span></font><b><font size=1 color=gray><span
style='font-size:8.0pt;color:gray;font-weight:bold'> </span></font></b><font
size=1 color=gray><span style='font-size:8.0pt;color:gray'><a
href="http://www.elmengr.com/" target="_blank"
title="blocked::http://www.elmengr.com/">www.elmengr.com</a></span></font><o:p></o:p></p>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 color="#1f497d" face="Times New Roman"><span style='font-size:11.0pt;
color:#1F497D'> </span></font><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;
border-color:-moz-use-text-color -moz-use-text-color'>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><font
size=2 face="Times New Roman"><span style='font-size:10.0pt;font-weight:bold'>From:</span></font></b><font
size=2><span style='font-size:10.0pt'> Nearedge [mailto:<a
href="mailto:near_ej@yahoo.com" target="_blank">near_ej@yahoo.com</a>] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, November 12, 2010
12:51 AM<br>
<b><span style='font-weight:bold'>To:</span></b> <a
href="mailto:cjaigath@yahoo.com" target="_blank">cjaigath@yahoo.com</a><br>
<b><span style='font-weight:bold'>Cc:</span></b> <a
href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Bldg-sim] Adjusting
Capacity for Unmet Cooling</span></font><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=2 face="Times New Roman"><span style='font-size:10.0pt'>Hello Jaigath,<br>
Using the performance rating method (PRM), in my experience it is usually an
issue of low supply CFM.<br>
Correct me if I am wrong but on the contrary I think that ASHARE baseline PRM fixes
the cooling and heating capacities to 1.15 and 1.25 respectively and the user
is allowed to bump up the supply CFM in increments if necessary.<br>
I have a feeling that the issue of unmet load hours has been discussed many
times before -- so, the archives will be a good resource as well.<br>
Best,<br>
Neeraj</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=2 face="Times New Roman"><span style='font-size:10.0pt'>Neeraj Kapoor<br>
t: +91.99581.70018</span></font><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><font
size=2 face="Times New Roman"><span style='font-size:10.0pt'>e:
neeraj[at]kalpakrit[dot]com<br>
Kalpakrit Sustainable Environments Pvt. Ltd.<br>
<a href="http://www.kalpakrit.com" target="_blank">www.kalpakrit.com</a></span></font><o:p></o:p></p>
<table class=MsoNormalTable border=0 cellpadding=0 width=405 style='width:303.75pt'>
<tr>
<td valign=top style='padding:1.5pt 1.5pt 1.5pt 1.5pt'>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><u><font
size=2 face="Times New Roman"><span style='font-size:10.0pt'>Office Address</span></font></u><font
size=2><span style='font-size:10.0pt'>:<br>
610-A Udyog Vihar, Phase-5,<br>
Gurgaon, Haryana - 122016<br>
t: +91.124.430.9490/ 1/ 2<br>
f: +91.124.430.9493</span></font><o:p></o:p></p>
</td>
<td valign=top style='padding:1.5pt 1.5pt 1.5pt 1.5pt'>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><u><font
size=2 face="Times New Roman"><span style='font-size:10.0pt'>Registered
Address</span></font></u><font size=2><span style='font-size:10.0pt'>:<br>
101 Anupam Apartments,<br>
<st1:Street w:st="on"><st1:address w:st="on">Mehrauli-Badarpur Road</st1:address></st1:Street>,<br>
<st1:City w:st="on"><st1:place w:st="on">New Delhi</st1:place></st1:City> -
110068</span></font><o:p></o:p></p>
</td>
</tr>
</table>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>On 11-11-2010
10:30, Jaigath Chandraprakash wrote: <o:p></o:p></span></font></p>
<div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>Hello All,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>I would like to
know how other increase their baseline capacity when they have unmet load. I
have a PSZHP system and in one system, I got more than 400 hrs unmet load. I
usually just increase the TR cooling capacity until I get a lower unmet load
but in this case, I think the unmet load is due to low supply cfm. Is it ok to
adjust also the supply fan cfm? I am thinking that G3.1.2.2 only requires me to
adjust only the cooling capacity. Do others adjust both cfm and cooling load?<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>Thanks,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'>Jaigath<o:p></o:p></span></font></p>
</div>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
</div>
</div>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'><br>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br clear=all>
<br>
-- <br>
Carol Gardner PE<o:p></o:p></span></font></p>
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