<BODY onload=parent.init() contentEditable=true><P>Design Loads Programs use generated weather for each day of a typical day of month from the ASHRAE percent design conditions for summer & winter. <SPAN style="mso-spacerun: yes"> </SPAN>It is a guide and not a standard that has to be followed.<SPAN style="mso-spacerun: yes"> </SPAN>It is used to size equipment.<SPAN style="mso-spacerun: yes"> </SPAN>ASHRAE 99% winter design -16 degF but it can go down to -40 degF.<SPAN style="mso-spacerun: yes"> </SPAN>Actual weather data can result in overestimating and underestimating.<SPAN style="mso-spacerun: yes"> </SPAN><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></P>
<P style="MARGIN: auto 0in" class=MsoNoSpacing>See <A href="http://bepan.info/engg-calcs"><FONT color=#0000ff>http://bepan.info/engg-calcs</FONT></A> Item <A href="http://bepan.info/yahoo_site_admin/assets/docs/3a_-_Design-Weather-Generator.28122750.xls"><FONT color=#0000ff>3a - Design-Weather-Generator</FONT></A><o:p></o:p></P>
<P style="MARGIN: auto 0in" class=MsoNoSpacing>and <A href="http://bepan.info/hvac-prog/x1-apec-hccv-loads"><FONT color=#0000ff>http://bepan.info/hvac-prog/x1-apec-hccv-loads</FONT></A><o:p></o:p></P>
<P style="MARGIN: auto 0in" class=MsoNoSpacing>You can down the APEC HCCV Loads program and try it (does not work on 64-bit)<o:p></o:p></P>
<P style="MARGIN: auto 0in" class=MsoNoSpacing><A href="http://bepan.info/yahoo_site_admin/assets/docs/Disk1.3104039.zip"><FONT color=#0000ff>HCC-Disk-1</FONT></A> <A href="http://bepan.info/yahoo_site_admin/assets/docs/Disk2.3104054.zip" type=4><FONT color=#0000ff>HCC-Disk2</FONT></A><o:p></o:p></P>
<P style="MARGIN: auto 0in" class=MsoNoSpacing>Varkie<o:p></o:p></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">Milda,<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">If you did notice, HAP </SPAN><B style="mso-bidi-font-weight: normal"><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; COLOR: #c00000; FONT-SIZE: 10pt">uses two different weather files. one for design and other for simulation</SPAN></B><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">. And if you dig into it you'll find out that they both are different. The simulation weather is the real time (actual) temperature and other data recorded at the airports for an extended period, which cannot be overridden, while design weather data is based on extreme or peak weather as defined by ASHRAE which you can change in the program.<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt"><BR>Now if you are looking at LEED unmet load hours they may not be necessarily due to air sytem size, but may also be due to your plant insufficient capacity. Download HAP e help 014 from here :<A href="http://www.commercial.carrier.com/commercial/hvac/general/0,,CLI1_DIV12_ETI3906_MID1738,00.html" target=1><FONT color=#0000ff>http://www.commercial.carrier.com/commercial/hvac/general/0,,CLI1_DIV12_ETI3906_MID1738,00.html</FONT></A>.<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">In here you will find a pdf saying understanding the LEED unmet load hours in HAP.<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">Simulation results is just for us to know how the building would run in real time when sized on the design results. In simulation , HAP takes credit of internal heat gains, which reduces your heating load, which is OK in real time. While in design , internal heat gain is ignored in heating load calcualtions. This is just one of the difference in simulation and design in HAP.<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 12pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">I hope this helps Milda.<BR style="mso-special-character: line-break"><BR style="mso-special-character: line-break"><o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">On Tue, Apr 5, 2011 at 12:01 PM, milda margarin <<A href="javascript:main.compose('new','t=empire999@hotmail.com')"><FONT color=#0000ff>empire999@hotmail.com</FONT></A>> wrote:<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">hi Varun <o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">thanks for your reply! I have another question though based on your statement that the system should be based on the 'design results'; I thought the whole point of using simulations is to predict the peak capacity required and then base your design on this? (possibly by applying safety factors according to real life experience).<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">And how can you have unmet loads when you design based on the peak load? In that case the 'peak load' is not the maximum load?<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">Further comments anybody?<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">best regards<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN style="LINE-HEIGHT: 115%; FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt">Milda<o:p></o:p></SPAN></P></BODY>