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Michael,<br>
Fans (and pumps) in TRNSYS set the downstream flow rate based on
the input control signal and the rated flow rate parameter. They use
the input flow rate only to check the fan mass balance. If you have
0 kg/h of air entering a fan because of the connections that you've
made and the fan's control signal is set to 1 and its rated flow
rate is 1000 kg/h then the fan will put out 1000 kg/h of air and log
the time step as having a mass imbalance. Sometimes this is not a
problem; for example if you have a fan that is blowing air from
ambient into an air handler or into a building. You don't really
care how much air is going into the fan and you can either ignore
the warning or connect the fan's output flow rate to its input to
suppress the message. If you have a supply / return system then it
is probably more important to make sure that flow is balancing
around the loop. Use a type65 and plot the flow rate out of each
device in the loop. Make sure it all sums to the fan's outlet flow
rate.<br>
Best,<br>
David<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/4/2012 01:21, Michael Diekerhof
wrote:<br>
</div>
<blockquote cite="mid:50BDA48B.2010509@web.de" type="cite">
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<div class="moz-cite-prefix">David,<br>
thanks for this fast reply. Since I connected the pressure as
well (don´t know how i could miss this) there are no more
warnings due to psychometrics. Just at the end there´s one
warning left, which doesn´t sound good:<br>
<br>
<i>*** Warning at time : 8760.000000</i><i><br>
</i><i> Generated by Unit : 6</i><i><br>
</i><i> Generated by Type : 112</i><i><br>
</i><i> Message : Fan mass balance failed
during 35040 timesteps. Please check the connections.</i><br>
<br>
Do you have any idea what in detail could be wrong ? I made the
connections for dry bulb, humidity and pressure. <br>
<br>
Thanks in advance!<br>
Best,<br>
Michael <br>
<br>
<br>
<br>
<br>
Am 12/3/2012 6:39 PM, schrieb David BRADLEY:<br>
</div>
<blockquote cite="mid:50BCE3D1.6090508@tess-inc.com" type="cite">
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
Michael,<br>
You need to connect the pressure as well. It is surprising
that you always get the warning. I would understand if you get
that warning for some timesteps (maybe even enough timesteps to
go over the allowable number of warnings in a simulation.
However, if you get that warning at every single timestep, there
might be something else wrong.<br>
Regards,<br>
David<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/3/2012 05:39, Michael
Diekerhof wrote:<br>
</div>
<blockquote
cite="mid:trinity-a9d1d262-dda8-4b33-b262-3defa7db93eb-1354534798680@3capp-webde-bs27"
type="cite">
<div style="font-family: Verdana;font-size: 12.0px;">
<div>Dear all,<br>
</div>
<div><br>
</div>
<div>I´m using type 112 as a fan for an air-Source heat pump
(type401). <br>
</div>
<div><br>
</div>
<div>Between Type 15(weather) and type 112 i made the
following connections:<br>
</div>
<div><br>
</div>
<div>Dry bulb temperature => Inlet temperature<br>
</div>
<div>Humity ratio => Inlet air humidity ratio<br>
</div>
<div><br>
</div>
<div>But unfortunetaly I do always receive the following
warning which results in an Error:<br>
</div>
<div><br>
</div>
<div><em>"The referenced UNIT has called the PSYCHROMETRICS
routine witha humidity ratio above the saturation
humidity ratio for the given dry bulb temperature. <br>
</em></div>
<div><em>The air was assumed saturated at the given dry bulb
temperature and the humidity ratio set for this
condition</em>"<br>
</div>
<div><br>
</div>
<div>Does anyone has a suggestion to solve this problem ?? I
appreciate any idea :)<br>
</div>
<div><br>
</div>
<div>Best,<br>
Michael <br>
</div>
</div>
<br>
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<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 moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:d.bradley@tess-inc.com">d.bradley@tess-inc.com</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a>
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</blockquote>
<br>
</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>
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