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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>I changed the topic name to �Equipment Sizing�.<SPAN style="mso-spacerun: yes"> </SPAN>I thought I would add my 2 cents worth also. So now Bldg-Sim has 8 cents worth.<o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>The first building project that I was associated was at the tail end of the M-E design at JB&B of the Federal Reserve Bank Building in Minneapolis.<o:p></o:p></FONT></SPAN></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><A href="http://www.lera.com/projects/ofc/federalreservemn.htm"><FONT color=#0000ff face=Calibri>http://www.lera.com/projects/ofc/federalreservemn.htm</FONT></A><o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>The building opened in January (I think) in the early 70s.<SPAN style="mso-spacerun: yes"> </SPAN>ASHRAE winter design at 1% is -16 F.<SPAN style="mso-spacerun: yes"> </SPAN>When the building opened it was about -30 F (it can go down to -40 F there) with strong winds.<SPAN style="mso-spacerun: yes"> </SPAN>Occupants in the US are not dressed (with full arm and leg heavy woolen underwear) to tolerate low indoor temps even for one day.<SPAN style="mso-spacerun: yes"> </SPAN><o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>Summer design in Minneapolis at 1% is 92 DB 75 WB but the DB can exceed 100 F.<SPAN style="mso-spacerun: yes"> </SPAN>Occupants can tolerate a little discomfort on the few days that extreme summer conditions occur.<SPAN style="mso-spacerun: yes"> </SPAN>It�s still better than no AC. <SPAN style="mso-spacerun: yes"> </SPAN>Few, if any, buildings were air-conditioned, even in the US, before 1940.<SPAN style="mso-spacerun: yes"> </SPAN>The moral of this story is design for extreme winter conditions in very cold climates.<SPAN style="mso-spacerun: yes"> </SPAN>Judgment, experience, and common sense have to be applied.<SPAN style="mso-spacerun: yes"> </SPAN>It depends on the location.<SPAN style="mso-spacerun: yes"> </SPAN>In a place like Singapore the temp varies from a low of 75 F to 95 F all day and all year.<SPAN style="mso-spacerun: yes">
</SPAN>There are no extremes.<SPAN style="mso-spacerun: yes"> </SPAN>All buildings in tropical countries do not need heating systems.<o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>Inefficient energy use occurs when there is only one unit of the equipment and it is oversized.<SPAN style="mso-spacerun: yes"> </SPAN>When there are two or more units, one unit starts until it reaches maximum, then second unit comes on and the two shares load.<SPAN style="mso-spacerun: yes"> </SPAN>The units are rarely operated at minimum load.<SPAN style="mso-spacerun: yes"> </SPAN>This is the default in DOE2 but LOAD-MANAGEMENT allows you to sequence the use of primary equipment in any way you want that is appropriate for the project.<o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>The lighting and equipment design criteria was 5 watts /sf and 3 watts /sf for buildings designed before the energy crises in 1974.<SPAN style="mso-spacerun: yes"> </SPAN>No one cared about energy before then.<SPAN style="mso-spacerun: yes"> </SPAN>Actual lighting density was nowhere close, and there was very little equipment in offices.<SPAN style="mso-spacerun: yes"> </SPAN>This means for a million sqft building you end up with three chillers.<SPAN style="mso-spacerun: yes"> </SPAN>One is standby which comes into operation when a chiller fails or one chiller has to be shut down for maintenance.<SPAN style="mso-spacerun: yes"> </SPAN>Specifying standby primary equipment affects first costs and does not affect equipment efficiency.<o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>Energy programs are for comparing alternative energy conservation measures.<SPAN style="mso-spacerun: yes"> </SPAN>There is no need to size equipment for occasional extreme weather conditions.<SPAN style="mso-spacerun: yes"> </SPAN>But I think auto-sizing is based on weather data (not design data or median weather data) so equipment is sized for the worst condition of that year.<SPAN style="mso-spacerun: yes"> </SPAN>This means at every other hour of the year the equipment is operating inefficiently at part load conditions.<SPAN style="mso-spacerun: yes"> </SPAN>Equipment sizes estimated by energy programs are used in the design process.<o:p></o:p></FONT></SPAN></P>
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<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>Equipment schedules in design documents are based on actual equipment selected from manufacturers catalogs.<SPAN style="mso-spacerun: yes"> </SPAN>The name of the manufacturer and the model number are specified and then �or equal� added.<SPAN style="mso-spacerun: yes"> </SPAN>Equipment schedules are not based on design calculations or generic data because it is possible that real equipment cannot meet the performance data.<SPAN style="mso-spacerun: yes"> </SPAN>You need the dimensions of the equipment (with clearances for maintenance) to design them into the space.<SPAN style="mso-spacerun: yes"> </SPAN>TRACE energy program is based on actual real equipment performance data specified my model numbers. <SPAN style="mso-spacerun: yes"> </SPAN>HAP is based on real equipment, but they don�t mention model numbers.<o:p></o:p></FONT></SPAN></P>
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<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><FONT face=Calibri><SPAN style="FONT-SIZE: 12pt">I think the Code of Federal Regulations 10CFR434 (</SPAN><SPAN style="FONT-SIZE: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold">ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS)</SPAN><SPAN style="FONT-SIZE: 12pt"> used to allow you to size two identical units of primary equipment each at 66% of the maximum design.<SPAN style="mso-spacerun: yes"> </SPAN>This would be commercial buildings with large heating and cooling loads where you would have two units.<SPAN style="mso-spacerun: yes"> </SPAN>Perhaps it was a special case where failure to perform at all times was not an option.<SPAN style="mso-spacerun: yes"> </SPAN>I couldn�t find it the latest register.<o:p></o:p></SPAN></FONT></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><SPAN style="FONT-SIZE: 12pt"><A href="http://www.wbdg.org/pdfs/10cfr434.pdf"><FONT color=#0000ff face=Calibri>http://www.wbdg.org/pdfs/10cfr434.pdf</FONT></A><o:p></o:p></SPAN></P>
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<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><I style="mso-bidi-font-style: normal"><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>10CFR434 - 403.2.2 <SPAN style="mso-bidi-font-style: italic">Equipment and System Sizing.<o:p></o:p></SPAN></FONT></SPAN></I></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><I style="mso-bidi-font-style: normal"><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>Heating and cooling equipment and systems shall be sized to provide no more than the loads calculated in accordance with subsection 403.2.1. A single piece of equipment providing both heating and cooling must satisfy this provision for one function with the other function sized as small as possible to meet the load, within available equipment options. Exceptions are as follows:<o:p></o:p></FONT></SPAN></I></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><I style="mso-bidi-font-style: normal"><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>(a) When the equipment selected is the smallest size needed to meet the load within available options of the desired equipment line. <o:p></o:p></FONT></SPAN></I></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><I style="mso-bidi-font-style: normal"><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>(b) Standby equipment provided with controls and devices that allow such equipment to operate automatically only when the primary equipment is not operating.<o:p></o:p></FONT></SPAN></I></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt; mso-layout-grid-align: none" class=MsoNormal><I style="mso-bidi-font-style: normal"><SPAN style="FONT-SIZE: 12pt"><FONT face=Calibri>(c) Multiple units of the same equipment type with combined capacities exceeding the design load and provided with controls that sequence or otherwise optimally control the operation of each unit based on load.<o:p></o:p></FONT></SPAN></I></P>
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