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<P>Dear TRNSYS Users:</P>
<P>I would like to compare the performance of some american solar collectors with some european ones. So far I understand, the thermal performance coefficients test for collectors used in Europe and the US are based on diifferent temperature differences ((Ti - Ta) in the US and (Tm - Ta) in Europe).</P>
<P>I would like to convert one type of equation into the other and compare the coefficents. So I Read the TRNSYS Manual, and they convert the equation with the coefficients <FONT size=3>a</FONT><FONT size=1>M</FONT>, <FONT size=3>a</FONT><FONT size=1>N</FONT> and <FONT size=3>a</FONT><FONT size=1>2</FONT> into an equivalent one with <FONT size=3>c</FONT><FONT size=1>R</FONT>(taualpha)<FONT size=1>n </FONT>and <FONT size=3>c</FONT><FONT size=1>R</FONT><FONT size=3>r</FONT> as coefficients. Then they use some correction factors to change between a function of (T<FONT size=1>i</FONT> - Ta) and a function of (T<FONT size=1>m</FONT> - T<FONT size=1>a</FONT>). But they have still the efficiency equation in terms of c<FONT size=1>R</FONT>(taualpha)<FONT size=1>n</FONT>/ c<FONT size=1>avg</FONT>(taualpha)<FONT size=1>n </FONT><FONT size=2>and c<FONT size=1>R</FONT><FONT size=3>r / c<FONT size=1>avg</FONT><FONT size=3>r.</FONT></FONT></FONT></P>
<P><FONT style="FONT-SIZE: 11px; FONT-FAMILY: tahoma,sans-serif"><FONT size=2>How can I obtain from these coefficients again the coeffcients a<FONT size=1>M</FONT>, <FONT size=3>a</FONT><FONT size=1>N</FONT> and <FONT size=3>a<FONT size=1>2</FONT>. </FONT></FONT><FONT size=2>It is possible to do that? In other words, it is possible from the coefficients a<FONT size=1>M</FONT>, <FONT size=3>a</FONT><FONT size=1>N</FONT> and <FONT size=3>a<FONT size=1>2 </FONT></FONT></FONT><FONT size=2>from test based on the temp. difference T<FONT size=1>i</FONT> - Ta) obtain the three coefficients a<FONT size=1>M</FONT>, <FONT size=3>a</FONT><FONT size=1>N</FONT> and <FONT size=3>a<FONT size=1>2 </FONT></FONT></FONT><FONT size=2>for the efficiency equation based on the temp. difference T<FONT size=1>m</FONT> - T<FONT size=1>a</FONT></FONT></FONT></P>
<P><FONT style="FONT-SIZE: 11px; FONT-FAMILY: tahoma,sans-serif"><FONT size=2>I dont know if I have explained my problem clearly. Thank you in advance for any possible help or comment.</FONT></FONT></P>
<P><FONT style="FONT-SIZE: 11px; FONT-FAMILY: tahoma,sans-serif"><FONT size=2>Best Regards</FONT></FONT></P>
<P><FONT style="FONT-SIZE: 11px; FONT-FAMILY: tahoma,sans-serif"><FONT size=2>José Luis Corrales Ciganda</FONT></FONT></P>
<P><FONT style="FONT-SIZE: 11px; FONT-FAMILY: tahoma,sans-serif"><FONT size=2></FONT> </P></DIV></FONT></div><br clear=all><hr>Consigue aquí las mejores y mas recientes ofertas de trabajo en América Latina y USA: <a href="http://g.msn.com/8HMAES/2743??PS=47575" target="_top">Haz clic aquí...</a> </html>