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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'>An example of sizing Fan Terminal Units
(FTU)….<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>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I have a 1000 cfm zone (determined from
peak load conditions) to be served by a FTU, therefore the parallel fan in my
box is sized for 500 cfm (50% of peak flow). Now typically in heating is
when the primary air is going to go to an absolute minimum. This must be
300 cfm or the total volume of OSA that I need for the zone, whichever is
larger. In theory, the fan could provide all 500 cfm of its air when the
primary air is at a minimum if that meets the load. The fan will
typically always be the first stage of heating. After that, if setpoint
isn’t met, the reheat coil comes on. I would say that the design
condition, depending on climate of course, will be cooling dominated 7 times
out of 10.<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'>Also, as a note, the discussion of minimum
flow setpoint is an area of weakness for a VAV system. If the zone was
designed for 1000 cfm in cooling mode and the minimum outside air was
determined to be 300 cfm, you will almost never reach this value when the VAV
is operating at part load. There is a good article on this in the January
issue of Engineered Systems magazine.<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>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hope this helps.<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>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Regards,<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><b><font size=1 color=black face="Trebuchet MS"><span style='font-size:7.5pt;
font-family:"Trebuchet MS";color:black;font-weight:bold'>Andrew Craig, EIT,LEED
AP</span></font></b><b><font size=1 color="#663300" face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:#663300;font-weight:
bold'>/</span></font></b><font size=1 color=black face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:black'> Mechanical
Designer</span></font><font size=1 color=navy face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:navy'> <br>
</span></font><b><font size=1 color="#663300" face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:#663300;font-weight:
bold'>INTERFACE</span></font></b><font size=1 color="#663300"
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:#663300'> ENGINEERING</span></font><font size=1 color=navy
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:navy'> <br>
</span></font><b><font size=1 color=black face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:black;font-weight:bold'>direct</span></font></b><font
size=1 color=black face="Trebuchet MS"><span style='font-size:7.5pt;font-family:
"Trebuchet MS";color:black'> 503.382.2696</span></font><font size=1 color=navy
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:navy'> </span></font><o:p></o:p></p>
</div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<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'> Chien Si
Harriman [mailto:chien.harriman@iesve.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, February 21, 2008
2:25 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Andrew Craig<br>
<b><span style='font-weight:bold'>Cc:</span></b> bldg-sim@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> FW: [Bldg-sim] FW:</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>
<div id=idOWAReplyText84428>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Hi Andrew, that is really
helpful. I missed that section of the code.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Now, a few points that maybe someone could elucidate, maybe
even you:</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>1.) Does 50% of the peak design flow rate imply that,
if, for example, the min vol setpoint is 30%, then the recirc coming in
parallel is 20%?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>2.) That makes sense, except I am guessing
this CFM value is the 50% peak design flow rate? That would only be
logical.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>3.) This min setpoint is for the primary air.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>4.) The design condition they are referring to is the
summer design condition, or the winter design condition or both? I am
guessing it is both.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>That is a great help, thanks for everything so far.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Sincerely,</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Chien</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabIndex=-1>
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<p class=MsoNormal style='margin-bottom:12.0pt'><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'> Andrew
Craig [mailto:andrew_c@ieice.com]<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thu 21/02/2008 22:12<br>
<b><span style='font-weight:bold'>To:</span></b> Chien Si Harriman;
bldg-sim@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [Bldg-sim] FW:</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Chien---</span></font><o:p></o:p></p>
<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><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Section G3.1.3.14 of Appendix G hit on
requirements for fan powered boxes. They are:</span></font><o:p></o:p></p>
<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-left:.5in;text-indent:-.25in'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>1.)</span></font><font size=1 color=navy><span style='font-size:
7.0pt;color:navy'> </span></font><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>FTUs shall be sized for 50% of the peak design flow rate </span></font><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in;text-indent:-.25in'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>2.)</span></font><font size=1 color=navy><span style='font-size:
7.0pt;color:navy'> </span></font><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>FTUs shall be modeled with 0.35 W/cfm fan power.</span></font><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in;text-indent:-.25in'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>3.)</span></font><font size=1 color=navy><span style='font-size:
7.0pt;color:navy'> </span></font><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Minimum volume setpoints for FTUs shall be equal to 30% of the peak
design flow rate or the rate required to meet minimum OSA ventilation,
whichever is larger.</span></font><o:p></o:p></p>
<p class=MsoNormal style='margin-left:.5in;text-indent:-.25in'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>4.)</span></font><font size=1 color=navy><span style='font-size:
7.0pt;color:navy'> </span></font><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>The supply air temperature setpoint shall be constant at the design
condition.</span></font><o:p></o:p></p>
<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><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hope that helps. Good luck.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><br>
Regards,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<div>
<p><b><font size=1 color=black face="Trebuchet MS"><span style='font-size:7.5pt;
font-family:"Trebuchet MS";color:black;font-weight:bold'>Andrew Craig, EIT,LEED
AP</span></font></b><b><font size=1 color="#663300" face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:#663300;font-weight:
bold'>/</span></font></b><font size=1 color=black face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:black'> Mechanical
Designer</span></font><font size=1 color=navy face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:navy'> <br>
</span></font><b><font size=1 color="#663300" face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:#663300;font-weight:
bold'>INTERFACE</span></font></b><font size=1 color="#663300"
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:#663300'> ENGINEERING</span></font><font size=1 color=navy
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:navy'> <br>
</span></font><b><font size=1 color=black face="Trebuchet MS"><span
style='font-size:7.5pt;font-family:"Trebuchet MS";color:black;font-weight:bold'>direct</span></font></b><font
size=1 color=black face="Trebuchet MS"><span style='font-size:7.5pt;font-family:
"Trebuchet MS";color:black'> 503.382.2696</span></font><font size=1 color=navy
face="Trebuchet MS"><span style='font-size:7.5pt;font-family:"Trebuchet MS";
color:navy'> </span></font><o:p></o:p></p>
</div>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<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>Chien Si Harriman<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, February 21, 2008
2:07 PM<br>
<b><span style='font-weight:bold'>To:</span></b> bldg-sim@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Bldg-sim] FW:</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>
<div id=idOWAReplyText94559>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabIndex=-1>
</span></font></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><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'> Chien Si
Harriman<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thu 21/02/2008 21:46<br>
<b><span style='font-weight:bold'>To:</span></b> bldg-sim@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> </span></font><o:p></o:p></p>
</div>
<div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Hi there-</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I've been tasked with modeling a parallel fan powered box as
my baseline system for ASHRAE 90.1 Appendix G, and basically I am wondering if
there is anyone who knows of modeling guidelines for that FPB? I have the
capability of modeling any sort of conditions I would like, so I can vary the
flow rate of the recirc air, the control sequencing of the fan-assist, and even
whether that fan is variable volume or constant volume.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I can't find any guidelines that exist anywhere on this
topic in ASHRAE 90.1, and this is the first time I've had to model it (I've
never designed an electrically-heated building before). Does anyone know
whether:</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>1.) There is a specific ratio for the amount of recirc
air to minimum primary air?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>2.) Whether the amount of recirc air should vary (ie-a
variable speed fan)?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>3.) You can just use a real FPB with data from a
company like Carrier, and just call it a day on the simultion effort?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Any guidance would be really helpful.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks in advance,</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Chien Harriman</span></font><o:p></o:p></p>
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