All Discussions Tagged 'transient' - Home Energy Pros2014-09-30T16:58:54Zhttp://homeenergypros.lbl.gov/group/buildingsimulations/forum/topic/listForTag?tag=transient&feed=yes&xn_auth=noTransient Heat Transfer Analysistag:homeenergypros.lbl.gov,2013-12-09:6069565:Topic:1447292013-12-09T16:42:45.811ZJames Whitehttp://homeenergypros.lbl.gov/profile/JamesWhite
<p><a href="http://api.ning.com:80/files/-TI4uM2ffQi**1WBUwfEUkvZVkCSzD44cTW*5S0ABC-0cnSiB3h4mzwUN29-XwXji9mgiPLQE7Rb1G1h4GiNWD5m9IGtm7UA/WallTemperatureProfile.png" target="_self"><img class="align-full" src="http://api.ning.com:80/files/-TI4uM2ffQi**1WBUwfEUkvZVkCSzD44cTW*5S0ABC-0cnSiB3h4mzwUN29-XwXji9mgiPLQE7Rb1G1h4GiNWD5m9IGtm7UA/WallTemperatureProfile.png?width=750" width="750"></img></a></p>
<p>I have put together an Excel spreadsheet that calculates the temperature profile through a wall that is heated by the sun.</p>
<p>It use the matrix [K]{T} + [C]{dT/dt} = {S}, where [K] is the heat transfer, {T} is the temperature at the various nodes, [C] is the thermal capacitance of the node,…</p>
<p><a href="http://api.ning.com:80/files/-TI4uM2ffQi**1WBUwfEUkvZVkCSzD44cTW*5S0ABC-0cnSiB3h4mzwUN29-XwXji9mgiPLQE7Rb1G1h4GiNWD5m9IGtm7UA/WallTemperatureProfile.png" target="_self"><img class="align-full" src="http://api.ning.com:80/files/-TI4uM2ffQi**1WBUwfEUkvZVkCSzD44cTW*5S0ABC-0cnSiB3h4mzwUN29-XwXji9mgiPLQE7Rb1G1h4GiNWD5m9IGtm7UA/WallTemperatureProfile.png?width=750" width="750"/></a></p>
<p>I have put together an Excel spreadsheet that calculates the temperature profile through a wall that is heated by the sun.</p>
<p>It use the matrix [K]{T} + [C]{dT/dt} = {S}, where [K] is the heat transfer, {T} is the temperature at the various nodes, [C] is the thermal capacitance of the node, and {S} is the thermal heat gain of the outer node. A copy of the spreadsheet and matrix math is attached.</p>
<p>The math equations have not been verified for accuracy or errors, but it is kind of fun to play around with the variables to see how the temperature profile in the wall changes throughout the day.</p>
<p><em>(Note that an earlier version of this post had the attached Excel file as a *.zip file. It has been replaced with an Excel version.)</em></p>