<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div style=""><blockquote type="cite" class=""><div class="">On Jul 24, 2015, at 1:42 PM, David BRADLEY <<a href="mailto:d.bradley@tess-inc.com" class="">d.bradley@tess-inc.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
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Zhe,<br class="">
TRNBuild has two concepts that are important here. An "airnode" is
an area of the building that can be represented by a single air
temperature. A "radiation zone" is volume within the building in
which all of the walls can "see" each other. How you decide to break
up the building into airnodes and radiation zones depends on what is
crossing the boundaries between them. For example if you have an
atrium with a glass roof or a glass wall there is going to be
vertical stratification (i.e. multiple airnodes) and it is the solar
radiation that is going to cross the airnode boundaries so you'll
combine those airnodes into a single radiation zone. Virtual
surfaces are used as boundaries between the airnodes because
radiation can cross a virtual surface.<br class="">
<br class="">
In your case, I think you have a greenhouse attached to the side
of a building so that there will certainly be a temperature
difference between the greenhouse and the rest of the building but
there probably won't be very much radiation crossing the boundary
between the two. In this case there isn't any need to define a
virtual surface because there isn't much radiation passing. You can
define there to be a "wall" between the two airnodes when you are
drawing the building in SketchUp. Then when you go to TRNBuild, you
can set that wall's properties so that it has a very low thermal
resistance (high u value). In this way the wall will allow you to
define convection between the two airnodes and there will be little
resistance to conduction heat transfer. <br class="">
<br class="">
best,<br class="">
David<br class="">
<br class="">
<br class="">
<br class="">
<div class="moz-cite-prefix">On 07/20/2015 19:17, Zhe Kong wrote:<br class="">
</div>
<blockquote cite="mid:CAEV5NyeDn3BXPPaT-ieS-3FjC4bo22OPyKU7yhZe0nOs=b2CQQ@mail.gmail.com" type="cite" class="">
<div dir="ltr" class="">Hi everyone:
<div class="">I just star learning Trnsys and come up with a basic
inquiry. Does anyone know how to create two airnodes within
one zone in sketchup before exporting into Trnsys? <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px;" class="">We
want to build a one-floor greenhouse mostly enclosed by
glazing. The sloped roofs are also in glazing. We want to do
the calculation concerning solar radiation and heat flow
without HVAC system. </span></div>
<div class="">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><br class="">
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class="">Currently
we built two zones (the plant one and the air one) with the
mutual surface set as virtual surface; however, even the two
virtual surfaces disappeared when being exported into
Trnsys, the two zones seemed to have no air flow connection.
The results show that the plant zone has small range of
temperature change, while the air zone has a much larger
range. We realized we should build the sketchup model with
two airnodes and one zone, but we didn't figure out how to
do it. Another question is, in that case, is there anyway we
can set different inputs according to the two airnodes?</div>
<div class=""><br class="">
</div>
<div class="">Thank you in advance. </div>
-- <br class="">
<div class="gmail_signature">
<div class=""><em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">Zhe
Kong</span></em></div>
<div class=""><em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">PhD
Student</span></em><br style="font-family:'Times New
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<em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">University
of Wisconsin - Milwaukee </span></em><br style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class="">
<em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">School
of Architecture and Urban Planning </span></em><br style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class="">
<em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">2131 E.
Hartford Ave, Milwaukee, WI 53211 </span></em><br style="font-family:'Times New
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<em style="font-family:'Times New
Roman';font-size:medium;background-color:rgb(255,255,255)" class=""><span style="font-family:arial,helvetica,sans-serif" class="">Office
327</span></em></div>
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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 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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