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<div class=Section1>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>James,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I see your argument that it is a challenge to design to 22
W/gpm. However, using your example of 2,000 gpm and 22 W/gpm, are you
suggesting that a 44 kW (60-hp) motor is acceptable for a
primary-only pump on a 1,000-ton chiller?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Section 11 states that the 22 W/gpm was chosen based on 75 ft of
head and 65% combined pump/motor efficiency (the 90.1 User’s Guide actually
says 60%) for a primary-only loop. This would include all system pressure
drops. Again, this is not easy to design to. But at least the Section 11
example is clear on how much pump energy to include in the baseline design.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>John<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:gray'>John T. Forester, P.E., LEED AP, Mechanical Design Engineer </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I BVH
Integrated Services I</span></b><b><span style='font-size:8.5pt;font-family:
"Arial","sans-serif";color:black'> </span></b><span style='font-size:8.5pt;
font-family:"Arial","sans-serif";color:gray'>617.658.9008 tel </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I</span></b><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'> </span></b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'>617.244.3753
fax</span><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'> </span><b><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'>I</span></b><b><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:gray'> </span></b><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:gray'>One Gateway Center Suite 506, Newton MA 02458 </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I <a
href="http://www.bvhis.com">www.bvhis.com</a> I Hartford ● New Haven
● Boston</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p></o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'> James Hansen
[mailto:JHANSEN@ghtltd.com] <br>
<b>Sent:</b> Tuesday, November 16, 2010 10:23 AM<br>
<b>To:</b> Richard Ellison; John T. Forester;
equest-users@lists.onebuilding.org<br>
<b>Subject:</b> RE: [Equest-users] Baseline Chilled Water Loop<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>As I indicated earlier, everyone has their own opinion about
this credit. But consider this:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The pressure drop across a cooling tower and condenser water
piping system is roughly the same as the pressure drop thru the chiller
evaporator and primary loop of a primary/secondary chilled water plant (on a
per gpm basis once you correct for the higher flow rates of the condenser
side). In other words, on a PER GPM basis, a typical water-cooled chilled
water plant will have similar pump HP per GPM for the condenser water system
and primary chilled water system. Not identical, but similar. I’ve
got 10+ recent base-building designs that confirm this. 90.1 requires 19
W / gpm for a condenser water system, and you are saying that you only model 6
W / gpm for the primary chilled water pump? That is below realistic
design values for a primary system, at least in my opinion. <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Example: 1,000 ton chiller at 54/42 requiring 2,000
GPM. 6 W / gpm thru the primary loop would only use 12.0 KW, or a 15 hp
motor frame. If you assume a chiller evaporator loss of 15 ft, and make
only modest estimates of an additional 20 ft for piping losses, strainers,
mixing valves, bypass valves, etc (35 ft total), you can try and select any
pump you want but you’re going to need at least a 25 hp motor. And with
most chilled water plants, even 35 ft seems low for the pressure drop across a
primary loop. I don’t see how 6 W / gpm can accurately represent a
chilled water primary loop even in the most efficient central plant
designs. <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Furthermore, if ASHRAE had wanted us to prorate the 22 W / gpm
between the primary and secondary loops, wouldn’t they have instructed us to do
that, especially since there is a huge difference in energy consumption
depending on which of the two loops has the higher W / gpm? Have they
instructed us to do that in an addendum?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I stand by my use of 22 W / gpm for each pump, and have never
had a reviewer instruct me to do otherwise (which of course doesn’t mean that
I’m not wrong). <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:teal'>GHT Limited<br>
</span></b><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif"'><ns0:PersonName><span
style='color:black'>James Hansen</span></ns0:PersonName></span></b><b><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'>, PE,
LEED AP<o:p></o:p></span></b></p>
<p class=MsoNormal><b><span style='font-family:"Arial","sans-serif";color:black'>Senior
Associate</span></b><b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:black'><o:p></o:p></span></b></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif"'><ns0:Street><ns0:address><span
style='color:black'>1010 N. Glebe Rd, Suite 200</span></ns0:address></ns0:Street></span><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif"'><ns0:place><ns0:City><span
style='color:black'>Arlington</span></ns0:City><span style='color:black'>, </span><ns0:State><span
style='color:black'>VA</span></ns0:State><span style='color:black'> </span><ns0:PostalCode><span
style='color:black'>22201-4749</span></ns0:PostalCode></ns0:place></span><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-338-5754 (Cell)</span><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-243-1200 (Office)</span><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-276-1376 (Fax)</span><span style='font-size:11.0pt;font-family:
"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:teal'><a href="http://www.ghtltd.com/"><span style='font-size:10.0pt'>www.ghtltd.com</span></a><o:p></o:p></span></p>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#31849B'><o:p> </o:p></span></b></p>
</div>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'> Richard Ellison
[mailto:REllison@southlandind.com] <br>
<b>Sent:</b> Tuesday, November 16, 2010 9:27 AM<br>
<b>To:</b> James Hansen; John T. Forester; equest-users@lists.onebuilding.org<br>
<b>Subject:</b> RE: [Equest-users] Baseline Chilled Water Loop<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I usually don’t respond to the information on this forum but I
completely disagree with this latest e-mail.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The chilled water is supplied by a chiller not a pump.
“The baseline design pump power shall be 22 W / gpm” is for the GPM delivered
by the chiller and the pumping system does not matter. The power is specified
per GPM not per pump. If you use primary/secondary then the energy
is divided between the pumps. We usually assume 6W/gpm for the primary
pump and 16W/gpm for the secondary pump. If one uses 22W/gpm for each
pump, then the total of 44W/gpm the pump energy is huge and the savings
unrealistic.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;
font-family:"Arial","sans-serif";color:#1F497D'>R I C H A R D E L L I S O
N</span><span style='color:#E36C0A'><br>
</span><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>PE, CEM, CEA, CTAB, CBEP, LEED AP </span><o:p></o:p></p>
<p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;
font-family:"Arial","sans-serif";color:#1F497D'>Energy Engineer</span><span
style='color:#E36C0A'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Southland Industries</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>22340 Dresden Street, Suite 177</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Dulles, VA 20166</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Office: 703.834.5570</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Direct: 703.834.2438</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Fax: 703.834.5572</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'>
equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org]
<b>On Behalf Of </b>James Hansen<br>
<b>Sent:</b> Tuesday, November 16, 2010 8:50 AM<br>
<b>To:</b> John T. Forester; equest-users@lists.onebuilding.org<br>
<b>Subject:</b> Re: [Equest-users] Baseline Chilled Water Loop</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I’ve seen different people provide different responses to this
question, but I’ve always modeled EACH pump in a chilled water system as 22 W /
gpm. Don’t prorate.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>“The baseline design pump power shall be 22 W / gpm”. It
can’t be any more clear than this. 90.1 tells you when you need a primary
/ secondary system, and when you can get away with primary only. In other
words, they are telling you how many pumps you need to model. And they
specifically list the pump power in terms of GPM, which is PER PUMP.
Nowhere does it say to prorate.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<div>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:teal'>GHT Limited<br>
</span></b><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:black'>James Hansen</span></b><b><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'>, PE, LEED AP</span></b><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-family:"Arial","sans-serif";color:black'>Senior
Associate</span></b><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>1010 N. Glebe Rd, Suite 200</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>Arlington, VA 22201-4749</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-338-5754 (Cell)</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-243-1200 (Office)</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-276-1376 (Fax)</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:teal'><a href="http://www.ghtltd.com/"><span style='font-size:10.0pt'>www.ghtltd.com</span></a></span><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#31849B'> </span></b><o:p></o:p></p>
</div>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'> equest-users-bounces@lists.onebuilding.org
[mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>John T.
Forester<br>
<b>Sent:</b> Tuesday, November 16, 2010 8:41 AM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> Re: [Equest-users] Baseline Chilled Water Loop</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Fellow Modelers,</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I’ve received a comment regarding my response last week on how
to model CHW pumps for App. G. Specifically, item 7 (see below) and how
the 22 W/gpm is defined for a primary secondary configuration.
Section G3.1.3.10 can be interpreted (at least) two different ways.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>First, Section G3.1.3.10 Chilled-Water Pumps (Systems 7 and 8)</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:0in;margin-right:203.25pt;
margin-bottom:0in;margin-left:.5in;margin-bottom:.0001pt'><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>“The
baseline design pump power shall be 22 W/gpm. Chilled-water systems
with a cooling capacity of 300 tons or more shall be modeled as primary/secondary
systems with variable-speed drives on the secondary pumping loop.
Chilled-water pumps in systems serving less than 300 tons cooling capacity
shall be modeled as primary/secondary systems with secondary pump riding the
pump curve.”</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The question: </span><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in'><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:#1F497D'>Should each primary and
secondary pump be sized for 22 W/gpm OR should this “design pump power” be
divided up (in some way) between the primary and secondary pumps?</span><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in'><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Position A:</span><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in'><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:#1F497D'>If the 22 W/gpm should be the
TOTAL pumping power, there is no guidance on how to divvy up this requirement
and the constant volume primary pumps could be sized for 20 W/gpm and the
secondary (VSD or riding pump curve) can be allotted 2 W/gpm. This
would maximize the pump energy in the baseline model.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Position B:</span><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in'><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:#1F497D'>Sizing each primary pump and
secondary pump to 22 W/gpm will over-estimate the baseline pump energy
(VSD or riding pump curve) and this is not the intent of 90.1. The
“design pump power” of 22 W/gpm is the same requirement as Section 11 (ECB
method) just with a different pumping configuration.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>How do you interpret (and model) 90.1 App. G chilled-water pump
power requirement of 22 W/gpm? (Your interpretation doesn’t
necessarily have to be one of the positions above.)</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Thanks,</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>John</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:gray'>John T. Forester, P.E., LEED AP, Mechanical Design Engineer </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I BVH
Integrated Services I</span></b><b><span style='font-size:8.5pt;font-family:
"Arial","sans-serif";color:black'> </span></b><span style='font-size:8.5pt;
font-family:"Arial","sans-serif";color:gray'>617.658.9008 tel </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I</span></b><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'> </span></b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'>617.244.3753
fax</span><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'> <b>I</b></span><b><span style='font-size:8.5pt;font-family:
"Arial","sans-serif";color:gray'> </span></b><span style='font-size:8.5pt;
font-family:"Arial","sans-serif";color:gray'>One Gateway Center Suite 506,
Newton MA 02458 </span><b><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'>I <a href="http://www.bvhis.com">www.bvhis.com</a> I
Hartford ● New Haven ● Boston</span></b><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'>
equest-users-bounces@lists.onebuilding.org
[mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>John T.
Forester<br>
<b>Sent:</b> Friday, November 12, 2010 5:47 PM<br>
<b>To:</b> 'Smith, Michael'<br>
<b>Cc:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> Re: [Equest-users] Baseline Chilled Water Loop</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi Michael,</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I think I can answer your App G question.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>First, in the context of 90.1, “variable flow” does not
necessarily mean variable speed. It just means riding the pump curve with
a bypass to minimize pumping pressure drops through the loop during part-load
operation.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><u><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>App. G Chilled Water Modeling <=300 tons</span></u><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create a chilled water circulation loop and name it something
like “Pri CHW Loop.”</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create another chilled water circulation loop and name it
something like “Sec CHW Loop.”</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Change
the Loop Sub-type of this loop to Secondary and choose “Pri CHW Loop” as the
primary loop.</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create a circulation pump and name it something like “Sec CHW
Pump.”</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Set
this pump as variable speed. I believe you are allowed to set the minimum
speed to 50% for App. G. (someone here on the list can correct me on this if
I’m wrong).</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>b.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>By
default, the valve on this loop is three-way and will circulate water directly
back to the primary loop as long as there are two-way valves at your terminal
units (AHU coils, FCUs, etc).</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>c.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Attach
this pump to the Sec CHW Loop.</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>d.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Change
the loop head sensor location to “at coils.”</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create a condenser water loop and CW pump and attach the pump to
the loop.</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Also
create an open tower heat rejection device and attach it to your condenser
water loop.</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>5.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create 1 primary chilled water pump per chiller. They
won’t be attached to anything yet and will be at the bottom of the component
tree.</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The
default for a pump is “One-Speed.” This is fine and the pump will act as
a constant volume pump with the three-way valve on the secondary loop.</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>6.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Create a water-cooled chiller and choose the “Pri CHW Loop 1”
and “water-cooled.”</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Since
there is no pump attached to the primary loop, you will be required to select a
pump for the chiller.</span><o:p></o:p></p>
<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>b.<span
style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You
will also be required to select the Condenser water loop</span><o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>7.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Now what you have to do is size your pumps so the total pump
energy is 22 W/pm. You will want to do something like 4-5 W/gpm for each
primary pump and use the remaining for the secondary pump.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>This system is primary/secondary with constant flow through each
chiller and variable speed/variable flow through the secondary loop.
Since each chiller has a pump directly attached to it, each primary pump will
automatically cycle on and off with the chillers.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:gray'>John T. Forester, P.E., LEED AP, Mechanical Design Engineer </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I BVH
Integrated Services I</span></b><b><span style='font-size:8.5pt;font-family:
"Arial","sans-serif";color:black'> </span></b><span style='font-size:8.5pt;
font-family:"Arial","sans-serif";color:gray'>617.658.9008 tel </span><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'>I</span></b><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'> </span></b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:gray'>617.244.3753
fax</span><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'> <b>I</b></span><b><span style='font-size:8.5pt;font-family:
"Arial","sans-serif";color:gray'> </span></b><span style='font-size:8.5pt;
font-family:"Arial","sans-serif";color:gray'>One Gateway Center Suite 506,
Newton MA 02458 </span><b><span style='font-size:8.5pt;font-family:"Arial","sans-serif";
color:#0000A0'>I </span></b><a href="http://www.bvhis.com"><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif"'>www.bvhis.com</span></b></a><b><span
style='font-size:8.5pt;font-family:"Arial","sans-serif";color:#0000A0'> I
Hartford ● New Haven ● Boston</span></b><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'>
equest-users-bounces@lists.onebuilding.org
[mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Smith,
Michael<br>
<b>Sent:</b> Friday, November 12, 2010 3:55 PM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> [Equest-users] Baseline Chilled Water Loop</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>Everyone,<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>I have a question regarding the baseline chilled water loop.
<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>ASHRAE 90.1 2007 Section G3.1.3.10 states that for large
chilled water systems serving baseline systems 7 and 8 that are greater than
300 tons the loop “shall be modeled as primary/secondary with variable speed
drives on the secondary pumping loop.”<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>The following section, G3.1.3.11 further goes on to say that
“each chiller shall be modeled with separate…chilled water pumps interlocked to
operate with the associated chiller.”<o:p></o:p></p>
<p class=MsoNormal style='margin-top:12.0pt'>As clarification, does this mean
three sets of pumps are required, or just two? Are the “primary” loop pumps
specified as the chiller pumps? <o:p></o:p></p>
<p class=MsoNormal style='margin-top:12.0pt'>Two reasons why I am confused.
Firstly, the Chapter 11 baseline chilled water loop is supposed to be simulated
as primary-only variable flow, but still has the similar requirement for
interlocked chiller pumps. That would be two sets of pumps. Adding a
“secondary” loop actually adds a third set of pumps. <o:p></o:p></p>
<p class=MsoNormal style='margin-top:12.0pt'>The second reason why I am
confused is that the <a
href="http://www.energydesignresources.com/Portals/0/documents/DesignGuidelines/EDR_DesignGuidelines_%20HVAC_Simulation.pdf">Simulation
Guidebook</a> prepared for Pacific Gas and Electric (same affiliation as
CoolTools) has a visual of how to simulate “primary/secondary” loops on page
52, but they do not include chiller pumps in their image of the eQUEST
component tree. <o:p></o:p></p>
<p class=MsoNormal style='margin-top:12.0pt'>I can’t understand why three sets
of pumps would be required. I supposed a follow up question may be if the 22
watts/gpm is inclusive of all three sets of pumps. Hopefully someone can
clarify! I appreciate your help. <o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> </span><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-family:"Arial","sans-serif";color:#333399'>Michael
J. Smith, EIT, LEED</span></b><sup><span style='font-family:"Arial","sans-serif";
color:#333399'>® </span></sup><b><span style='font-family:"Arial","sans-serif";
color:#333399'>AP</span></b><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif";
color:#333399'>WSP</span></b><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif";
color:#0069FB'> </span></b><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif";
color:#333399'>▪</span></b><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif";
color:#0069FB'> </span></b><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif";
color:black'>FLACK + KURTZ</span></b><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#66737D'>512 7th Ave., New York, NY 10018</span></b><o:p></o:p></p>
<p class=MsoNormal><b><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#66737D'>Direct: 212.951.2671| Main: 212.532.9600</span></b><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#66737D'><a href="http://www.wspfk.com/" title="http://www.wspfk.com/">www.wspfk.com</a></span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:8.0pt;font-family:"Arial","sans-serif";
color:#66737D'> </span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
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