<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>Thank you Karen, Joe, and everyone for your advice. </DIV>
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<DIV>To answer your question if the building has an economizer, no it does not have an economizer. I have also asked the mechanical designer regarding the electrical load in his design criteria and he did confirmed that his assumptions are typical for this type of building. I am really tempted to adjust the electrical load because it is too high compared to typical offices and I agree with you Karen that equipment do runs only at a fraction of the day.</DIV>
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<DIV>Thanks again,</DIV>
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<DIV>Jaigath <BR></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Karen Walkerman <kwalkerman@gmail.com><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Jaigath Chandraprakash <cjaigath@yahoo.com><BR><B><SPAN style="FONT-WEIGHT: bold">Cc:</SPAN></B> bldg-sim@lists.onebuilding.org<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Fri, September 24, 2010 7:14:47 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [Bldg-sim] Unusual Result<BR></FONT><BR>
<META http-equiv=x-dns-prefetch-control content=off>If most of your cooling loads come from internal loads as you said, then having windows with a higher U-value allows the building to lose heat to the outside any time it is cooler outside than inside. If you look at ASHRAE 90.1, the requirements for windows changes dramatically as you move from colder to warmer zones. In warmer zones, the allowed U-value is higher, but the SHGC is lower.
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<DIV>Also, it is usually good to verify that this is actually the case, often installed equipment runs only a fraction of the day, or at a fraction of the peak energy use. If your internal loads are not actually as high as you are modeling, this could change things.</DIV>
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<DIV>Lastly, does the building have an economizer? This may make sense for this particular project.</DIV>
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<DIV>--</DIV>
<DIV>Karen<BR><BR>
<DIV class=gmail_quote>On Fri, Sep 24, 2010 at 5:59 AM, Jaigath Chandraprakash <SPAN dir=ltr><<A href="mailto:cjaigath@yahoo.com" target=_blank rel=nofollow ymailto="mailto:cjaigath@yahoo.com">cjaigath@yahoo.com</A>></SPAN> wrote:<BR>
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<DIV>The project I am working on is an office building that operates 20 hrs per day with most of the loads occuring at night and low occupancy on daytime. It is a cooled by a DX roof unit and has a very high internal load. No heating equipment is required because the building is in Climate 1. I was surprised that when I changed my window U-value from 0.3 to 0.7 I got less cooling consumption. I always thought that getting low u-value will give me less coling consumption. Can somebody tell me why I am getting less cooling when I use a higher window U-value?</DIV>
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<DIV>Thanks,</DIV>
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<DIV>Jaigath</DIV></DIV><BR></DIV><BR>_______________________________________________<BR>Bldg-sim mailing list<BR>http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org<BR>To unsubscribe from this mailing list send a blank message to <A href="mailto:BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG" target=_blank rel=nofollow ymailto="mailto:BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG">BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG</A><BR><BR></BLOCKQUOTE></DIV><BR></DIV>
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