<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Chou,<br>
My apologies for the delay in getting back to you.<br>
<br>
<br>
<blockquote
cite="mid:CAP9LdPNKXUjWzYMeFMMTRXq6DES9qop41qamj4fTophx3JGwcw@mail.gmail.com"
type="cite"><span
style="font-size:10.5pt;font-family:"Calibri","sans-serif""
lang="EN-US"></span><span style="font-size: 10.5pt; font-family:
"Calibri","sans-serif";" lang="EN-US">1. As
you mentioned in the first simulation with Type 56----to get a
basic idea
of how much energy the building will consume, use the
VENTILATION Type with
outside air and use the COOLING Type to define set up
temperature. I set the
VENTILATION Type with the conditioned air (temperature 16C), I
think the
cooling load will change, but the results don't change
significantly (<10%).
Also in the VENTILATION Type, I wonder the air change rate
refers to the fresh
air or the mixed air (flow of fresh + return air) if the
VENTILATION is set up
as outside.<br>
</span></blockquote>
Type56's VENTILATION is quite simple; it is just an air flow rate
(specified in air changes in v16, and specified as either an air
change rate or a mass flow rate in v17) with the temperature and RH
that you specify. There is no assumption at all about whether it is
outside air or return air. From your description of adding a
VENTILATION type with a temperature of 16C, my guess is that your
cooling load was reduced by adding a cool stream of air to the room
(provided that your room setpoint is above 16C of course). The size
of the reduction would depend upon how much air you added. If you
specified a small amount of air, the reduction would be small. If
you specify the conditions of the VENTILATION types as "outside"
then Type56 simply adds the quantity of air that you specified and
uses the ambient conditions that it already knows from the ambient
temperature and RH inputs to the Type. In this case, you are adding
only the flow of fresh air. In order to add a mixed flow, you would
have to specify the air change rate of the mixed flow and the
conditions of the mixed flow, probably as additional INPUTS to
Type56.<br>
<blockquote
cite="mid:CAP9LdPNKXUjWzYMeFMMTRXq6DES9qop41qamj4fTophx3JGwcw@mail.gmail.com"
type="cite"><span style="font-size: 10.5pt; font-family:
"Calibri","sans-serif";" lang="EN-US">
2. In the file of BALANCE summary, the BAL_ENERGY is supposed to
be zero,
according to the Manual. However my results indicate that this
item is up to 10^6
kJ, and it doesn't equal to the sum of the other items. And
there is not too much details about it on the manual.<br>
</span></blockquote>
I would need to take a look at the input file in order to determine
whether or not this is expected.<br>
<blockquote
cite="mid:CAP9LdPNKXUjWzYMeFMMTRXq6DES9qop41qamj4fTophx3JGwcw@mail.gmail.com"
type="cite"><span
style="font-size:10.5pt;font-family:"Calibri","sans-serif""
lang="EN-US">
3. I try to use Type 53 + Type 52 as the AC components of the
Type 56, </span><span lang="EN-US">But when
I run the model, an error occurs, which says,<br>
<br>
</span>
<p class="MsoNormal" style="text-align:left" align="left"><span
lang="EN-US">TRNSYS
Message 350: Unable to open the file associated with an
ASSIGNED logical unit
number. Please check the statement and make sure that the file
exists at the
specified location. Reported information: Logical Unite=36,
FileName=.</span></p>
</blockquote>
the fact that the filename is blank in the error message is probably
an indication that you didn't specify a performance data file for
Type53. Try opening Type53 and selecting the "External Files" tab to
make sure that a file is referenced. An example file can be found
in:<br>
<br>
.Trnsys17\Examples\Data Files\Type53-ParallelChillers.dat. If you
are using Trnsys16, I can send you a copy of the file.<br>
<br>
Kind regards,<br>
David<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>