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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>I ran into this once on lab project in the northwest (mild climate). Turned out the higher performance glazing was trapping the high internal heat gains. Higher cooling energy and lower heating energy.</FONT></DIV>
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<P class=MsoNormal><B><FONT face=Arial color=#0069aa size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #0069aa; FONT-FAMILY: Arial">Joe Llona, P.E. LEEDŽ AP, CSBA </SPAN></FONT></B><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #939598; FONT-FAMILY: Arial">|<B><SPAN style="FONT-WEIGHT: bold"> </SPAN></B></SPAN></FONT><B><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #7d6a53; FONT-FAMILY: Arial">Senior Mechanical Engineer<BR></SPAN></FONT></B><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #7d6a53; FONT-FAMILY: Arial">Direct: 206.883.9318 | Main: 206.883.9300 | Fax: 206.883.9301<BR>joseph.llona@tetratech.com</SPAN></FONT><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #939598; FONT-FAMILY: Arial"><BR></SPAN></FONT><B><FONT face=Arial color=#005596 size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #005596; FONT-FAMILY: Arial"><BR></SPAN></FONT></B><B><FONT face=Arial color=#0069aa size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #0069aa; FONT-FAMILY: Arial">Tetra Tech</SPAN></FONT></B><B><FONT face=Arial color=#005596 size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #005596; FONT-FAMILY: Arial"> </SPAN></FONT></B><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #939598; FONT-FAMILY: Arial">|<B><SPAN style="FONT-WEIGHT: bold"> </SPAN></B></SPAN></FONT><B><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #7d6a53; FONT-FAMILY: Arial">Infrastructure Group<BR></SPAN></FONT></B><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #7d6a53; FONT-FAMILY: Arial">1420 Fifth Avenue, Suite 600</SPAN></FONT><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #7d6a53; FONT-FAMILY: Arial"> | Seattle, Washington 98101 | www.tetratech.com</SPAN></FONT><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 9pt; COLOR: #939598; FONT-FAMILY: Arial"><BR></SPAN></FONT><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 8pt; COLOR: #939598; FONT-FAMILY: Arial"><BR></SPAN></FONT><FONT face=Arial color=#7d6a53 size=1><SPAN style="FONT-SIZE: 8pt; COLOR: #7d6a53; FONT-FAMILY: Arial">PLEASE NOTE: This message, including any attachments, may include privileged, confidential and/or inside information. Any distribution or use of this communication by anyone other than the intended recipient is strictly prohibited and may be unlawful. If you are not the intended recipient, please notify the sender by replying to this message and then delete it from your system.</SPAN></FONT><FONT face=Arial color=#939598 size=1><SPAN style="FONT-SIZE: 8pt; COLOR: #939598; FONT-FAMILY: Arial"></SPAN></FONT></P> </FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> BLDG-SIM@gard.com on behalf of nicole chen<BR><B>Sent:</B> Mon 7/30/2007 1:03 AM<BR><B>To:</B> BLDG-SIM@gard.com<BR><B>Cc:</B> bldg-sim@gard.com<BR><B>Subject:</B> [BLDG-SIM] energy consumption of low-E glazing , why the cooling energy increases<BR></FONT><BR></DIV>
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<DIV>What I did is define a new glass type with simplied method in detailed model. Then replace the old glass with the new defined one. Can this do? How to avoid the defauls percolate through the program? I check again and find that there was no wrong with the conduction heat and solar radiation through window .But the load due to occupancy /lighting/euqipment of Glass Type II is higher than Glass Type I . And the cooling energy of Glass type II is a little highter. It make me confused. Why the load due to due to occupancy /lighting/euqipment was different when Glass type changed. </DIV>
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<DIV>And I doubt if the problem has something to do with OA load .<BR><BR> </DIV>
<DIV><SPAN class=gmail_quote>On 7/29/07, <B class=gmail_sendername>Karen Walkerman</B> <<A href="mailto:kwalkerman@gmail.com">kwalkerman@gmail.com</A>> wrote:</SPAN>
<BLOCKQUOTE class=gmail_quote style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi nicole,<BR><BR>I can't tell you why the heating energy of glass type II may be lower<BR>because of the better U-value. With Shading Coefficients almost the <BR>same, there should be little change in heat gain from solar radiation<BR>between the two types.<BR><BR>What method did you use to enter your data? You should be careful of<BR>defaults that can percolate through the program. For example, the <BR>window frame U-value may not be consistent, or the glass spacer-type<BR>may be different.<BR><BR>Another good place to look for some feedback is the building and space<BR>peak loads summary. Here, the solar gain (heat energy gained through <BR>radiation) and simple conditioning (energy transfered through the<BR>glass-same as walls), are broken out. The heating design case will<BR>not take solar radiation into account.<BR><BR>Hope this helps.<BR><BR>~karen~ <BR><BR>On 7/29/07, nicole chen <<A href="mailto:cloris.chen@gmail.com">cloris.chen@gmail.com</A>> wrote:<BR>> Dear all<BR>><BR>> I have tried to compare the energy consumption between two different glass<BR>> types and got a curious result. The parameters of these two glasses are<BR>> listed below:<BR>><BR>> 1) Coated U=2.5 SC=0.45<BR>> 2) low-e U=1.76 SC=0.44<BR>><BR>> I thought the energy consumption of Glass Type II would be lower than that <BR>> of Glass Type I . But the result is the cooling energy of Glass Type II is<BR>> higher than that of Glass Type I , and the heating energy lower than that<BR>> of Glass Type I.<BR>><BR>> I have no idea of this. And I checked LS-F/ SS-D / BEPS and found some <BR>> points listed below<BR>><BR>> 1) in LS-F annual sensible cooling load of Glass Type II is lower than that<BR>> of Glass Type I , latent cooling load of Glass Type II is higher. The total<BR>> annual cooling load of Glass Type II is a little higher <BR>><BR>> 2) in SS-D monthly cooling energy of Glass Type II is higher<BR>><BR>> 3) dencity and schedule of occupancy /lighting /euqipment are the same in<BR>> the two models , but cooling load and heating load due to these indoor <BR>> factors are different , why?<BR>><BR>> 4) monthly schedule of occupancy /lighting /euqipment is all the same<BR>> during the year, but cooling load and heating load due to these indoor<BR>> factors are different every month, why? <BR>><BR>><BR>><BR>> --<BR>> Yours<BR>> Nicole Chen<BR><BR><BR>--<BR>Karen Walkerman<BR>Second Law Consulting<BR>802-238-0980<BR><A href="mailto:kwalkerman@gmail.com">kwalkerman@gmail.com</A><BR></BLOCKQUOTE></DIV><BR><BR clear=all><BR>-- <BR>Yours<BR>Nicole Chen </DIV><PRE>
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