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<p class=MsoNormal><span style='color:#1F497D'>David &#8211; a couple follow-up
questions regarding the two separate circumstances you bring to light:<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2;
text-autospace:none'><![if !supportLists]><span style='color:#1F497D'><span
style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style='color:#1F497D'>Using Appendix G as
the governing authority for performing energy simulations<o:p></o:p></span></p>

<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l1 level2 lfo2;text-autospace:none'><![if !supportLists]><span
style='color:#1F497D'><span style='mso-list:Ignore'>a.<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style='color:#1F497D'>I now see that Section
G3.1.3.15 states &#8220;</span><span style='color:#1F497D'>VAV system supply
fans shall have variable speed drives&#8230;&#8221; with no mention of this
requirement applying only to individual fans greater than 15 hp.&nbsp; So, for
energy simulation purposes it seems the baseline is required to use VFD&#8217;s.</span><span
style='color:#1F497D'><o:p></o:p></span></p>

<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l1 level2 lfo2;text-autospace:none'><![if !supportLists]><span
style='color:#1F497D'><span style='mso-list:Ignore'>b.<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style='color:#1F497D'>The wording
specifically identifies &#8220;supply fans&#8221; but would this apply to return
or relief fans as well?&nbsp; Or, can the baseline return or relief fans be
modeled without VFD&#8217;s using constant volume w/ motorized damper on a
bypass loop modulated to maintain building pressure?<o:p></o:p></span></p>

<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo2;
text-autospace:none'><![if !supportLists]><span style='color:#1F497D'><span
style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style='color:#1F497D'>Using section 6 for
prescriptive code compliance.<o:p></o:p></span></p>

<p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;
mso-list:l1 level2 lfo2;text-autospace:none'><![if !supportLists]><span
style='color:#1F497D'><span style='mso-list:Ignore'>a.<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style='color:#1F497D'>Is it your
interpretation of Section 6.5.3.2.1 that fanwall air handlers using banks of
individual fans rated at less than 15 hp each would be exempt from the VFD
requirement?&nbsp; (i.e. Fanwall controlled simply by staging individual fans on/off
to maintain system flow &amp; pressure requirements would meet the intent of
this prescriptive section?) OR is this an unintended loop-hole in the wording
of the Standard?<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'>All
responses welcome, <o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'>Thanks,<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

<div>

<p class=MsoNormal><span style='font-size:14.0pt;font-family:Cheltenham;
color:#A0002F'>&nbsp;</span><span style='font-size:18.0pt;font-family:Cheltenham;
color:#A0002F'>Dan Russell, EIT <o:p></o:p></span></p>

<p class=MsoNormal><span style='font-size:10.0pt;font-family:Cheltenham;
color:#A0002F'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='font-size:10.0pt;font-family:Cheltenham;
color:#A0002F'><img width=200 height=174 id="_x0000_i1026"
src="cid:image001.jpg@01C9077B.006EC100"
alt="cid:image001.jpg@01C840A4.E711B250"></span><span style='color:#1F497D'><o:p></o:p></span></p>

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<p class=MsoNormal><span style='color:#1F497D'><o:p>&nbsp;</o:p></span></p>

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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> bldg-rate-bounces@lists.onebuilding.org
[mailto:bldg-rate-bounces@lists.onebuilding.org] <b>On Behalf Of </b>David S
Eldridge<br>
<b>Sent:</b> Tuesday, August 26, 2008 10:14 AM<br>
<b>To:</b> bldg-rate@lists.onebuilding.org<br>
<b>Subject:</b> Re: [Bldg-rate] ASHRAE 90.1 - VAV Fan Part-Load Power
Limitation<o:p></o:p></span></p>

</div>

</div>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal><span style='color:black'>The baseline building will still
be constructed in the same method using Appendix G regardless of your choice of
proposed AHU.&nbsp; The baseline system will have a single fan/motor AHU, and
it will have VAV characteristics if required based on the system selection
table and size of the system.<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:black'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:black'>The portion of the Standard 90.1
you are referring to in Section 6 is for prescriptive compliance.&nbsp; If your
project is using the prescriptive section for code submittal, then you just
have to meet or exceed those requirements without a quantification of
&#8220;how much better&#8221;.<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:black'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:black'>Hope this helps!<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:black'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:black'>David<o:p></o:p></span></p>

<p class=MsoNormal><span style='color:black'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='color:black'><o:p>&nbsp;</o:p></span></p>

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<div>

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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
bldg-rate-bounces@lists.onebuilding.org
[mailto:bldg-rate-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Dan
Russell<br>
<b>Sent:</b> Tuesday, August 26, 2008 10:04 AM<br>
<b>To:</b> bldg-rate@lists.onebuilding.org<br>
<b>Subject:</b> [Bldg-rate] ASHRAE 90.1 - VAV Fan Part-Load Power Limitation<o:p></o:p></span></p>

</div>

</div>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal>My question regards Section 6.5.3.2.1 Part-Load Fan Power
Limitation from ASHRAE Standard 90.1-2004, which states:<o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"TT118Co00","sans-serif"'>6.5.3.2.1 </span><b><span
style='font-size:10.0pt;font-family:"Times New Roman","serif"'>Part-Load Fan
Power Limitation. </span></b><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>Individual<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>VAV fans with motors 15 hp and larger
shall meet one of<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>the following:<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>(a) The fan shall be driven by a
mechanical or electrical variable-<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>speed drive.<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>(b) The fan shall be a vane-axial fan
with variable-pitch<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>blades.<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>(c) The fan shall have other controls and
devices that will<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>result in fan motor demand of no more
than 30% of<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>design wattage at 50% of design air
volume when static<o:p></o:p></span></p>

<p class=MsoNormal style='text-autospace:none'><span style='font-size:10.0pt;
font-family:"Times New Roman","serif"'>pressure setpoint equals one-third of
the total design static<o:p></o:p></span></p>

<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>pressure,
based on <i>manufacturer&#8217;s </i>certified fan data.</span><o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal>I have a project that is using Fanwall technology in the air
handlers that serve the VAV system.&nbsp; The air handler has 3 rows of 8 fans
each of them only 7.5 hp each (at total of 24 &#8211; 7.5 hp fans for a total
of 180 hp).&nbsp; When the Standard here says &#8220;Individual VAV fans&#8230;&#8221;
is it saying that for this type of air handler where no individual fan exceeds
15 hp that part-load control is not required?&nbsp; Certainly, if this is true,
using this technology would be great for demonstrating energy points (aka
LEED), but I&#8217;m having a hard time justifying this in my mind.<o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal>Does anyone know if this Section applies to
&#8220;fanwall&#8221; technology or if it is simply intended to make
distinction between supply, return, relief, and exhaust fans?<o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal>Thanks,<o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

<p class=MsoNormal><span style='font-size:14.0pt;font-family:Cheltenham;
color:#A0002F'>&nbsp;</span><span style='font-size:18.0pt;font-family:Cheltenham;
color:#A0002F'>Dan Russell, EIT <o:p></o:p></span></p>

<p class=MsoNormal><span style='font-size:10.0pt;font-family:Cheltenham;
color:#A0002F'><o:p>&nbsp;</o:p></span></p>

<p class=MsoNormal><span style='font-size:10.0pt;font-family:Cheltenham;
color:#A0002F'><img width=200 height=174 id="Picture_x0020_1"
src="cid:image001.jpg@01C9077B.006EC100"
alt="cid:image001.jpg@01C840A4.E711B250"></span><o:p></o:p></p>

<p class=MsoNormal><o:p>&nbsp;</o:p></p>

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