Jay Burch at NREL has developed an approach to calculate the thermal efficiency and the tank heat loss coefficient from the published energy factor test results. It's quite elegant and we use the approach all the time in our consulting projects. I can send you the algorithm if you'd like to use it.<BR><BR>Jeff<BR><!--{12222835332650}--><BR>Jeff Thornton <BR>President - TESS, LLC <BR><BR>2916 Marketplace Drive - Suite 104 <BR>Madison WI 53719 USA <BR><BR>Phone: 608-274-2577 <BR>Fax: 608-278-1475 <BR>E-mail: thornton@tess-inc.com <BR>Web: www.tess-inc.com<BR><BR><BR><BR>
<DIV id=replyfwdwrap style="BACKGROUND-POSITION: 50% top; BACKGROUND-IMAGE: url(http://webmail.fusemail.com/de/r_bg_img.gif); BACKGROUND-REPEAT: repeat-x"><STRONG>----- Original Message -----</STRONG><BR><STRONG>From:</STRONG> cj@cr-jay.ca<BR><STRONG>Sent:</STRONG> Wed, September 24, 2008 13:38<BR><STRONG>Subject:</STRONG> [Bldg-sim] Modelling service water heater<BR><BR>
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<DIV class=bodyclass>This question is about setting the efficiency of the budget case domestic hot water heater for modelling purposes. In 90.1-2004, Section 11.3.2 (b) is states "<FONT face="Times New Roman, Times">All HVAC and service water heating equipment in the <I>budget building </I>shall be modeled at the minimum <I>efficiency </I>levels, both part load and full load, in accordance with 6.4 and 7.4. <BR><BR></FONT>7.4 refers to Table 7.8. A small gas heated storage tank has an efficiency of 0.62-0.0019V EF. Where EF is the energy factor. From what I can find there is no single formula to convert EF to thermal efficiency. So what would you model the budget case efficiency at in DOE2.1e for this example?<BR><BR>Thanks for any insight you can give.<BR><BR><BR><BR><BR><BR><BR><X-SIGSEP>
<P></X-SIGSEP>Chris Jones, P.Eng.<BR>14 Oneida Avenue<BR>Toronto, ON M5J2E3<BR>Tel. 416 203-7465<BR>Fax. 416 946-1005</P></DIV><!--{12222835332652}-->
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