<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>My boss is a skeptic of the data presented in the System Sizing Tab that can be generated when you are the System screen and hit the Summary tab, and I don't have a good explanation. We looked at a single office floor in the Southern California are, a floor with about 50% glass and about 29,000 sf. The System tab generated a size of 107 tons (installed tonnage for the floor was 80 tons). Most load information was defaulted.</span></div><div><br><span></span></div><div><span>The installed tonnage was 80 tons and the unmet hours were few.<br></span></div><div><br><span></span></div><div><span>When we increased the airflow slightly, the load size was 80 tons. When we increased the total supply airflow double, the tonnage went to about 140 tons.</span></div><div><br><span></span></div><div><span>And, of course,
the unmet hours varied, inconsistent of course between SS-R and SS-F and the System Sizing tab.</span></div><div><span><br></span></div><div><span>All I am looking for is a detailed explanation of how the system sizing tab is generated. Obviously, this is not TRACE sizing routine, but there are some of us who must use this table to have a sense if a builidng has enough cooling after equipment (read-SERVERS) has been added to a floor.</span></div><div><span><br></span></div><div><span>Can anyone who had had time to research this care to share their finds?</span></div><div><span><br></span></div><div><span>Thanks.</span></div><div><span><br></span></div><div><span>John Aulbach.<br></span></div><div><br><span></span></div><div><span>What is <br></span></div><div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Arial"
size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Jun Furuta <JFuruta@energy-solution.com><br><b><span style="font-weight: bold;">To:</span></b> "equest-users@lists.onebuilding.org" <equest-users@lists.onebuilding.org><br><b><span style="font-weight: bold;">Sent:</span></b> Tuesday, September 20, 2011 1:39 PM<br><b><span style="font-weight: bold;">Subject:</span></b> [Equest-users] Modeling 2 stage cooling in a single zone packaged unit<br></font><br><div id="yiv450485664"><style><!--
#yiv450485664
_filtered #yiv450485664 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}
_filtered #yiv450485664 {font-family:Tahoma;panose-1:2 11 6 4 3 5 4 4 2 4;}
#yiv450485664
#yiv450485664 p.yiv450485664MsoNormal, #yiv450485664 li.yiv450485664MsoNormal, #yiv450485664 div.yiv450485664MsoNormal
{margin:0in;margin-bottom:.0001pt;font-size:11.0pt;font-family:"sans-serif";}
#yiv450485664 a:link, #yiv450485664 span.yiv450485664MsoHyperlink
{color:blue;text-decoration:underline;}
#yiv450485664 a:visited, #yiv450485664 span.yiv450485664MsoHyperlinkFollowed
{color:purple;text-decoration:underline;}
#yiv450485664 p.yiv450485664MsoAcetate, #yiv450485664 li.yiv450485664MsoAcetate, #yiv450485664 div.yiv450485664MsoAcetate
{margin:0in;margin-bottom:.0001pt;font-size:8.0pt;font-family:"sans-serif";}
#yiv450485664 span.yiv450485664EmailStyle17
{font-family:"sans-serif";color:windowtext;}
#yiv450485664 span.yiv450485664BalloonTextChar
{font-family:"sans-serif";}
#yiv450485664 .yiv450485664MsoChpDefault
{font-family:"sans-serif";}
_filtered #yiv450485664 {margin:1.0in 1.0in 1.0in 1.0in;}
#yiv450485664 div.yiv450485664WordSection1
{}
--></style><div class="yiv450485664WordSection1"><div class="yiv450485664MsoNormal">Hello,</div><div class="yiv450485664MsoNormal"> </div><div class="yiv450485664MsoNormal">I would like to model a packaged single zone AC with gas furnace that has two stage cooling with using two compressors. The system has an integrated economizer and a constant speed fan.</div><div class="yiv450485664MsoNormal"> </div><div class="yiv450485664MsoNormal"> Is there a way to indicate two compressors in the PSZ system type or am I supposed to use the PVVT system, despite being a single zone system and not having neither a variable speed compressor or fan? And if the PVVT system type is to be used, any advice on configuring the system would be greatly appreciated.</div><div class="yiv450485664MsoNormal"> </div><div class="yiv450485664MsoNormal">Thanks,</div><div class="yiv450485664MsoNormal"> </div><div
class="yiv450485664MsoNormal">-Jun</div><div class="yiv450485664MsoNormal"> </div><div class="yiv450485664MsoNormal"> </div></div></div><br>_______________________________________________<br>Equest-users mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org" target="_blank">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>To unsubscribe from this mailing list send a blank message to <a ymailto="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG" href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a><br><br><br></div></div></div></body></html>