<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
Johanes,<br>
I have not had a chance to look entirely at the issue yet.
However, as to your comment:<br>
<br>
"If this requirement dependent on the pipe spacing should be really
used for both layers, this would mean that extremely thick floor
screeds of +15cm are necessary to model a floor heating system with
a pipe spacing of 24 cm. This sounds absolutely unrealistic. "<br>
<br>
I run into similar problems with a lot of common radiant floor
configurations in the US. Radiant floors are often around 30cm pipe
spacing embedded in about 10cm of concrete. My sense was that
because the Type56 model is semi-empirical, what they were looking
to avoid in developing the correlation was any significant variation
in floor surface temperature (hotter right above a pipe, measurably
cooler between pipes). I also had the impression that European
installations also tended to favor less temperature variability. My
solution has usually been to keep the floor thickness as designed
and to reduce the pipe-to-pipe spacing as needed to get within the
model's allowable range. I wanted to avoid having more thermal
capacitance in my building that was really there and since we
usually ignore pressure drop, having more, thinner, closer spaced
pipes doesn't have a huge impact. I would be interested in hearing
other people's thoughts as well.<br>
<br>
Kind regards,<br>
David<br>
<br>
<br>
<br>
<br>
<br>
<br>
On 12/12/2011 06:48, Schrade, Johannes wrote:
<blockquote
cite="mid:76D707B03195C64E81A623DD170CDF3D049E9189@izs-xchg01.izs.fraunhofer.de"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<meta name="Generator" content="Microsoft Word 14 (filtered
medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
span.E-MailFormatvorlage17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 2.0cm 70.85pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:228614440;
mso-list-type:hybrid;
mso-list-template-ids:-298144564 67567617 67698691 67698693 67698689 67698691 67698693 67698689 67698691 67698693;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Symbol;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:"Courier New";}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;
font-family:Wingdings;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal">Dear TRNSYS users,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have some problems with the active layer
module of TRNBLD, which I used for modeling a floor heating
system.<o:p></o:p></p>
<p class="MsoNormal">The active layers, which should be
displayed in the model, are defined as following:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Layer 1:<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe spacing: 24 cm<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe outside diameter:
16 mm<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe wall thickness: 2
mm<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Layer 2:<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe spacing: 8 cm<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe outside diameter:
16 mm<o:p></o:p></p>
<p class="MsoListParagraph"
style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
style="font-family:Symbol"><span style="mso-list:Ignore">·<span
style="font:7.0pt "Times New Roman"">
</span></span></span><!--[endif]-->Pipe wall thickness: 2
mm<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">By specifying the thicknesses of the layers
adjacent to the active layers, the following curiosity
appeared.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">For case 1, I set the thickness of the
layer above the active layer to 73 mm, which is greater than
0.3 times the pipe spacing, and I set the layer below to 0.5
times the pipe outside diameter (requirements taken from
manual TRNSYS 17, 5-187, table). This step had worked pretty
good and the simulation was running without any problems.<o:p></o:p></p>
<p class="MsoNormal">In a second step, I revised the model and
included the second active layer into the TRNBLD model. As the
floor screed should be identical for both cases, I tried to
define the thicknesses of the adjacent layers the same way as
I did it in case 1. But when I tried to reduce the thickness
of the adjacent layer below, the following warning appeared:
“thickness must be in the range of 0.024 to 1.0”.<o:p></o:p></p>
<p class="MsoNormal">In order to understand this warning I had a
closer look to the manual of TRNBLD. On page 5-58 (TRNSYS 17)
I found a remark that both layers adjacent to the active layer
must be greater than 0.3 times pipe spacing. This would
explain, why the warning appears, but I do not understand, why
the first case should be unproblematic, as the required
minimum thickness in this case should be 72mm and why this is
not mentioned in the mathematical description.<o:p></o:p></p>
<p class="MsoNormal">Does anyone has an idea, what could be the
reason behind that, or might this be a known or unknown bug?
If this requirement dependent on the pipe spacing should be
really used for both layers, this would mean that extremely
thick floor screeds of +15cm are necessary to model a floor
heating system with a pipe spacing of 24 cm. This sounds
absolutely unrealistic. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hoping for some help,<o:p></o:p></p>
<p class="MsoNormal">Kind regards,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Johannes Schrade<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<table class="MsoNormalTable"
style="margin-left:3.0pt;border-collapse:collapse;border:none"
border="1" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td style="border:solid gray
1.0pt;border-right:none;padding:7.5pt 7.5pt 7.5pt 7.5pt">
<table class="MsoNormalTable"
style="margin-left:3.0pt;border-collapse:collapse;border:none"
border="1" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td style="border:solid gray 1.5pt;padding:3.0pt
3.0pt 3.0pt 3.0pt">
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><b><span
style="font-size:9.0pt;font-family:"Arial","sans-serif"">Johannes
Schrade</span></b><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><br>
Abteilung Wärmetechnik<o:p></o:p></span></p>
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><span
style="font-size:9.0pt;font-family:"Arial","sans-serif"">Fraunhofer-In</span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE">stitut für Bauphysik<br>
Nobelstr. 12<br>
70569 Stuttgart<o:p></o:p></span></p>
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><a
moz-do-not-send="true"
href="mailto:johannes.schrade@ibp.fraunhofer.de"><span
style="color:blue" lang="DE">johannes.schrade@ibp.fraunhofer.de</span></a></span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE"><br>
Telefon 0711 / 970-3416<br>
Telefax 0711 / 970-3399<br>
</span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><a
moz-do-not-send="true"
href="http://www.ibp.fraunhofer.de/wt/"
target="_blank"><span style="color:blue"
lang="DE">www.ibp.fraunhofer.de/wt/</span></a></span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE"><o:p></o:p></span></p>
</td>
</tr>
</tbody>
</table>
</td>
<td style="border:solid gray
1.0pt;border-left:none;padding:7.5pt 7.5pt 7.5pt 7.5pt">
<table class="MsoNormalTable"
style="margin-left:3.0pt;border-collapse:collapse;border:none"
border="1" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td style="border:solid gray 1.5pt;padding:3.0pt
3.0pt 3.0pt 3.0pt">
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><b><span
style="font-size:9.0pt;font-family:"Arial","sans-serif"">Johannes
Schrade</span></b><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><br>
Department Heat Technology <o:p></o:p></span></p>
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><span
style="font-size:9.0pt;font-family:"Arial","sans-serif"">Fraunhofer
Institute for Building Physics<br>
Nobelstr. </span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE">12<br>
70569 Stuttgart, Germany<o:p></o:p></span></p>
<p class="MsoNormal"
style="mso-margin-top-alt:6.0pt;margin-right:3.0pt;margin-bottom:6.0pt;margin-left:3.0pt"><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><a
moz-do-not-send="true"
href="mailto:johannes.schrade@ibp.fraunhofer.de"><span
style="color:blue" lang="DE">johannes.schrade@ibp.fraunhofer.de</span></a></span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE"><br>
Phone +49 711 / 970-3416<br>
Fax +49 711 / 970-3399<br>
</span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""><a
moz-do-not-send="true"
href="http://www.ibp.fraunhofer.de/wt/"
target="_blank"><span style="color:blue"
lang="DE">www.ibp.fraunhofer.de/wt/</span></a></span><span
style="font-size:9.0pt;font-family:"Arial","sans-serif""
lang="DE"><o:p></o:p></span></p>
</td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
<p class="MsoNormal"><span lang="DE"><o:p> </o:p></span></p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
TRNSYS-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TRNSYS-users@cae.wisc.edu">TRNSYS-users@cae.wisc.edu</a>
<a class="moz-txt-link-freetext" href="https://mailman.cae.wisc.edu/listinfo/trnsys-users">https://mailman.cae.wisc.edu/listinfo/trnsys-users</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI 53703 USA
P:+1.608.274.2577
F:+1.608.278.1475
<a class="moz-txt-link-abbreviated" href="mailto:d.bradley@tess-inc.com">d.bradley@tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.trnsys.com">http://www.trnsys.com</a></pre>
</body>
</html>