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Dapeng,<br>
While BESTEST (and ASHRAE Standard 140 - which is identical to
BESTEST) try hard to be very clear about what assumptions you should
make in each of the test cases, there is still <i>a lot</i> of room
for interpretation. Some years ago, we ran TRNSYS 16.1 through those
test cases as well and found that you can make quite legitimate
interpretations of the standard and come out with quite a variety of
results. I would recommend you have a look at a couple papers that
we wrote about the effort:<br>
<br>
"Converging on a Recommended Set of Interpretations and Assumptions
in Applying Standard Tests to Energy Analysis Tools"<br>
"Experiences with and Interpretations of Standard Test Methods of
Building Energy Analysis Tools"<br>
<br>
both are available at <a class="moz-txt-link-freetext" href="http://www.tess-inc.com/pubs">http://www.tess-inc.com/pubs</a>.<br>
<br>
If my recollection is correct, we were within the range on the 600
cases. If anything, the annual cooling that modern versions of
TRNSYS predict is on the low end of the range and is sometimes below
the range. It is worth keeping in mind that the "acceptable range"
of results does not come from an analytical solution. It comes from
the results generated by a bunch of software tools and TRNSYS
(version 13!) is one of them. Other software developers have
mentioned to me recently that building science and cooling load
algorithms have advanced since the 1980s and that more recent
algorithms do predict lower cooling loads than did the older
algorithms. This is not reflected in the BESTEST or Standard140
results; those ranges are still set by the older versions of the
tools. <br>
<br>
Best,<br>
David<br>
<br>
<br>
On 11/14/2011 21:14, Dapeng Li wrote:
<blockquote
cite="mid:CAE+QzVkE48exSZbThXF_jcQpA4NarHf87QMmAReNWTurZCDL=g@mail.gmail.com"
type="cite">
<div class="gmail_quote"><br>
Dear all users,
<div>Hello.</div>
<div><br>
</div>
<div>I try to take a test by using BESTEST algorithm. I use
TRNSYS version 16.01.003. I think I have taken my best to set
up each parameters in TRNSYS's deck and TRNBUILD according to
case 600's condition in the BESTEST documents which is
downloaded from <u style="color:rgb(0, 0, 128)"><a
moz-do-not-send="true"
href="http://www.nrel.gov/docs/legosti/old/6231.pdf"
target="_blank">http://www.nrel.gov/docs/legosti/old/6231.pdf</a>。</u><span
style="color:rgb(0, 0, 128)"> </span>But the annual heating
load (5.997MWh) from TRNSYS is different from the value ranges
(4.296 to 5.709). The annual cooling load (6.519MWh) fit well.
I wonder the reasons of this kind of difference. For
convenience, I attached my project for your deep examine.</div>
<div><br>
</div>
<div>Thank you for your help in advance. </div>
<div><br>
</div>
<div>kindly regards, </div>
<span class="HOEnZb"><font color="#888888">
<div>Dapeng Li</div>
<p style="margin-bottom:0in">
</p>
</font></span></div>
<br>
<br>
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<br>
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</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>
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