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<DIV>Dan,</DIV>
<DIV>If you are pursuing LEED points, A90.1 Appendix G outlines the fan power requirements and provides VAV fan part load performance requirements. If your baseline system is VAV, then it would need to utilize the G3.1.3.15 part load curve and the fan power limitations per Addendum ac or the fan power limits outlined in G3.1.2.9. Per Addendum ac, fan power is based on total system CFM for systems over 5 hp, not individual fan power. Section 6.5.3.2.1 largely applies for the ECB compliance path and the prescriptive compliance path, not performance comparisons like LEED.</DIV>
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<DIV>You could utilize a custom part load curve that reflects individual fans staging off in the fan wall system to take credit for improved part load conditions. My experience with fan wall is that system static pressure is reduced due to less system effect, sound attenuation reqs, etc., so perhaps your proposed fan power is lower than what is allowed for the baseline.</DIV>
<DIV>Regards,</DIV>
<DIV>Bill</DIV>
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<DIV> </DIV>
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<DIV><FONT face=Technic>Bill Talbert, PE, <SPAN style="FONT-SIZE: 12pt; LAYOUT-GRID-MODE: line; FONT-FAMILY: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA"><SPAN style="FONT-SIZE: 12pt; LAYOUT-GRID-MODE: line; FONT-FAMILY: Technic; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial"><FONT size=2>LEED® AP</FONT></SPAN></SPAN><BR>Mechanical Systems</FONT></DIV>
<DIV><FONT face=Technic>Phone: (608) 441-6677<BR>E-mail: btalbert@aeieng.com<BR><BR>Affiliated Engineers Inc.<BR>5802 Research Park Blvd.<BR>Madison, WI. 53719<BR>Tel. (608) 238-2616<BR>Fax. (608) 238-2614</FONT></DIV><BR><BR>>>> "Dan Russell" <danr@engineeringinc.com> 8/26/2008 10:04 AM >>><BR></DIV>
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<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:<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></P>
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<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'TT118Co00','sans-serif'">6.5.3.2.1 </SPAN><B><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman','serif'">Part-Load Fan Power Limitation. </SPAN></B><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman','serif'">Individual<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman','serif'">the following:<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman','serif'">speed drive.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman','serif'">blades.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; 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><SPAN style="FONT-SIZE: 10pt; 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: 10pt; FONT-FAMILY: 'Times New Roman','serif'">pressure, based on <I>manufacturer’s </I>certified fan data.</SPAN><o:p></o:p></P>
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<P class=MsoNormal>I have a project that is using Fanwall technology in the air handlers that serve the VAV system. The air handler has 3 rows of 8 fans each of them only 7.5 hp each (at total of 24 – 7.5 hp fans for a total of 180 hp). When the Standard here says “Individual VAV fans…” is it saying that for this type of air handler where no individual fan exceeds 15 hp that part-load control is not required? Certainly, if this is true, using this technology would be great for demonstrating energy points (aka LEED), but I’m having a hard time justifying this in my mind.<o:p></o:p></P>
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<P class=MsoNormal>Does anyone know if this Section applies to “fanwall” technology or if it is simply intended to make distinction between supply, return, relief, and exhaust fans?<o:p></o:p></P>
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<P class=MsoNormal>Thanks,<o:p></o:p></P>
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<P class=MsoNormal><SPAN style="FONT-SIZE: 14pt; COLOR: #a0002f; FONT-FAMILY: Cheltenham"> </SPAN><SPAN style="FONT-SIZE: 18pt; COLOR: #a0002f; FONT-FAMILY: Cheltenham">Dan Russell, EIT <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; COLOR: #a0002f; FONT-FAMILY: Cheltenham"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 10pt; COLOR: #a0002f; FONT-FAMILY: Cheltenham"><IMG id=Picture_x0020_1 height=174 alt=cid:image001.jpg@01C840A4.E711B250 src="cid:NEIDEJQNTBIQ.IMAGE.jpeg" width=200></SPAN><o:p></o:p></P>
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