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<DIV><STRONG><FONT size=2 face="Courier New">>Suppose we put the 5 groups of
containers above into a well-insulated tube A and make another<BR>tube B just
like A, and connect the dryer exhaust to one end of tube A, and the output of
A<BR>into tube B and the output of B to the dryer inlet. On the next load, we
swap A and B...<BR><BR>>Like
this:<BR>
--------------------------<BR> ---------------->------|---------X---<>|
120 110 100 90 80
|<>---<BR>| |
output
|
--------------------------
|<BR>|
|
|
A
| <BR>| dryer
|
|
|<BR>|
|
|
B
|<BR>| |
input
|
--------------------------
|<BR> ----------------<------X---------|---<>| 120 110
100 90 80
|<>---<BR>
--------------------------<BR><BR>>At an average 100 F in a 4'x7'x7'-tall box
with 210 ft^2 of R40 walls and a 5.25 Btu/h-F<BR>conductance, the tubes might
lose 24h(100-70)5.25 = 3780 Btu/day.<BR><BR>If the box is in a 70 F sunspace in
Phila in December with R2 sunspace glazing </FONT></STRONG><STRONG><FONT size=2
face="Courier New">with</FONT></STRONG></DIV>
<DIV><STRONG><FONT size=2 face="Courier New">81% solar transmission and 1 ft^2
of R1 box glazing with 90% solar transmission</FONT></STRONG></DIV>
<DIV><STRONG><FONT size=2 face="Courier New">gains 0.9x0.81x1000-6h(100-70)/R1 =
549 Btu/day, we can solar heat it with </FONT></STRONG></DIV>
<DIV><STRONG><FONT size=2 face="Courier New">3780/549 = 6.9 ft^2 of passive
solar air heater glazing. <BR><BR>Nick</FONT></STRONG></DIV></BODY></HTML>