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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=054484814-29042004>Hi
All-</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=054484814-29042004></SPAN></FONT> </DIV>
<DIV><SPAN class=054484814-29042004><FONT face=Arial><FONT color=#0000ff><FONT
size=2>What would happen if you forced economizer operation below 55F using the
cooling availability schedule set up as ON/OFF/Temp and designating
cooling during the spring, winter and fall as only available when OD temp
is above 55F? Would this <SPAN class=501000015-29042004>then
</SPAN><SPAN class=501000015-29042004>force the VAV system to increase airflow
to the required zones to satisfy cooling requirements (at the expense of
increased fan energy)?</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=054484814-29042004><SPAN
class=501000015-29042004></SPAN></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=054484814-29042004><SPAN
class=501000015-29042004></SPAN></SPAN></FONT></FONT></FONT> </DIV>
<DIV><SPAN class=501000015-29042004><FONT face=Arial color=#0000ff
size=2>Thanks,</FONT></SPAN></DIV>
<DIV><SPAN class=501000015-29042004><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=054484814-29042004>Sheila
Sagerer</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=054484814-29042004>Energy
Engineer</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=054484814-29042004>Energy
Opportunities, Inc</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=054484814-29042004>717-880-9069</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=054484814-29042004>Fax
717-291-9497</SPAN></FONT></DIV></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> postman@gard.com
[mailto:postman@gard.com]<B>On Behalf Of </B>Pat Bailey<BR><B>Sent:</B>
Wednesday, April 28, 2004 5:21 PM<BR><B>To:</B>
BLDG-SIM@GARD.COM<BR><B>Cc:</B> postman@gard.com<BR><B>Subject:</B> [BLDG-SIM]
eQUEST/economizer<BR><BR></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004>David,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004>We've run into this as well. One issue that is
relatively common with simulated VAV systems is that the economizer operation
and the VAV box operation can be completely independent of each other, even if
you don't want them to be. This may or might not be an issue in an
actual system depending on how the controls are configured. Even if the
design flow of outside air is sufficient to cool a zone, the reduced
flow at some level of VAV turndown may not be sufficient. For
this reason, there are hours of the year (typically cooler periods) when a
constant volume unit may show less simulated cooling energy.
</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=251270821-28042004>One
solution to this is to schedule increased levels of outside air during cooler
months, perhaps in the morning. The solution depends on when the cooling
load is not being met by outside air alone. </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=251270821-28042004>You
can also set the priorities of air flow and temperature reset. Varying
these will impact the trade off between fan energy and cooling
energy.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=251270821-28042004>Good
luck.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=251270821-28042004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=251270821-28042004>
<P><FONT size=2>_______________________</FONT></P>
<P><FONT size=2>Pat Bailey, P.E.<BR>Principal<BR>GeoPraxis, Inc<BR>205 Keller
Street<BR>Petaluma, CA 94952<BR><BR>www.geopraxis.com<BR>707.766.7010
(v)<BR>707.766.7014 (f)</FONT> </P></SPAN></FONT></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> postman@gard.com
[mailto:]<B>On Behalf Of </B>David Lanceta<BR><B>Sent:</B> Wednesday, April
28, 2004 11:35 AM<BR><B>To:</B> BLDG-SIM@GARD.COM<BR><B>Subject:</B>
[BLDG-SIM] eQUEST/economizer<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Hi everybody!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>First of all, I would like to say thank you to
everybody that have helped me in the past, I used to send emails to everyone
but I´m sure I´ve forgotten some of them.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I´m simulating an office building with eQUEST,
and I´m trying to know how much energy can be saved up. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>The HVAC system type is "Standard VAV with HW
Reheat" for all the zones, the cold deck reset is 55ºF. I´ve also set up a
drybulb temperature economizer, high limit 65ºF.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I think that when the drybulb
exterior temperature is below 55ºF there should be free-cooling,
but checking the temperature values this only happens when it´s under
49ºF </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>does anybody know why it could be?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>thanks</FONT></DIV>
<DIV><FONT face=Arial size=2>=================================<BR>David
Lanceta <BR>Área de Mecánica de Fluidos<BR>Centro Politécnico
Superior<BR>Universidad de Zaragoza<BR>María de Luna 3, tel (0034)9761000
ext 5044<BR>50015 ZARAGOZA<BR>ESPAÑA<BR></FONT></DIV><PRE>==================
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