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<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2><SPAN class=640503816-28102008><FONT face="Times New Roman"
color=#000000 size=3> </FONT><FONT face=Arial color=#0000ff size=2>my 2
cents..</FONT></SPAN></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2>I can attest first hand to having witnessed ERV systems
operating in a "FLOAT" mode that were using chilled water for cooling on a
50-degree day because heat recovery increased SAT to ~67F and they then
proceeded to cool SA back down to 55F.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2>I believe equest folks made the ERV default "FLOAT" so that
people would at least stop and think about the fact that an improperly
designed ERV system will actually increase energy use.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2>Mike</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640503816-28102008>
<DIV align=left><FONT face="Arial Black" size=2>Michael Tillou, PE,
LEED</FONT></DIV>
<DIV align=left><FONT face="Arial Black" size=2>Tillou Engineering,
LLC</FONT></DIV>
<DIV align=left><FONT face="Arial Black"
size=1></FONT> </DIV></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> bldg-sim-bounces@lists.onebuilding.org
[mailto:bldg-sim-bounces@lists.onebuilding.org] <B>On Behalf Of </B>Brian
Fountain<BR><B>Sent:</B> Tuesday, October 28, 2008 11:29 AM<BR><B>To:</B>
Xiaobing Liu; bldg-sim@lists.onebuilding.org<BR><B>Subject:</B> Re: [Bldg-sim]
ERV with increasing cooling load<BR></FONT><BR></DIV>
<DIV></DIV>The eQUEST default for temperature control is FLOAT whereby the heat
recovery device aims to maximize heat recovery for all ambient conditions.
This leads to heat recovery when economizer free cooling would be
preferable.<BR><BR>With "Mixed Air Reset", the device is modulated, either by
bypassing air or by modulating the heat exchanger (slowing the wheel), to
maintain the mixed air temperature at the mixed air temperature setpoint --
which is typically the supply air temperature setpoint less a couple of degrees
for fan pick-up. This is definitely a common building automation system
strategy.<BR><BR>Xiaobing Liu wrote:
<BLOCKQUOTE
cite=mid:4356BBD2A1FD7547B10BB742FFAD4B20074C24D4@lsbsrvr04.lsb-okc.com
type="cite">
<META content="MSHTML 6.00.2900.3354" name=GENERATOR>
<DIV><SPAN class=543091215-28102008><FONT face=Arial color=#0000ff size=2>I'm
wondering whether the Mixed Air Reset will really be implemented in the
real system? How big difference the air temperature control strategy will
make?</FONT></SPAN></DIV>
<DIV><SPAN class=543091215-28102008></SPAN> </DIV>
<DIV><SPAN class=543091215-28102008><FONT face=Arial color=#0000ff
size=2>Xiaobing</FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> <A
class=moz-txt-link-abbreviated
href="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A>
[<A class=moz-txt-link-freetext
href="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>]<B>On
Behalf Of </B>eric wang<BR><B>Sent:</B> Tuesday, October 28, 2008 10:06
AM<BR><B>To:</B> <A class=moz-txt-link-abbreviated
href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A>;
Kingsley, Michael L.<BR><B>Subject:</B> Re: [Bldg-sim] ERV with increasing
cooling load<BR><BR></FONT></DIV>
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<DIV id=yiv1804779766>
<DIV>Hi,</DIV>
<DIV> </DIV>
<DIV>Thanks a lot for all your replies. I changed the following
settings and solved the problem.</DIV>
<DIV> </DIV>
<DIV>Control Sequences Operation: when minimum OA </DIV>
<DIV>Make air temperature cotrol: Mixed Air Reset</DIV>
<DIV> </DIV>
<DIV>Best,</DIV>
<DIV> </DIV>
<DIV>Shaojie<BR><BR>--- On <B>Tue, 10/28/08, Kingsley, Michael L.
<I><A class=moz-txt-link-rfc2396E
href="mailto:MICHAEL.L.KINGSLEY@saic.com"><MICHAEL.L.KINGSLEY@saic.com></A></I></B>
wrote:<BR></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid">From:
Kingsley, Michael L. <A class=moz-txt-link-rfc2396E
href="mailto:MICHAEL.L.KINGSLEY@saic.com"><MICHAEL.L.KINGSLEY@saic.com></A><BR>Subject:
RE: [Bldg-sim] ERV with increasing cooling load<BR>To: <A
class=moz-txt-link-abbreviated
href="mailto:shaojieworld2006@yahoo.com">shaojieworld2006@yahoo.com</A>,
<A class=moz-txt-link-abbreviated
href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A><BR>Date:
Tuesday, October 28, 2008, 8:09 AM<BR><BR><PRE>Shaojie,
Check to make sure that you are not recovering heat during hours that
you can be using the economizer. Choose the Control Sequences:
Operation: "When Minimum OA" so that the heat recovery device will
only
operate when you cannot benefit from free cooling.
Mike
Michael L. Kingsley, PhD, PE, LEED AP
Senior Engineer/ Project Manager
SAIC
6390 Fly Road
East Syracuse, New York 13057
Phone: (315) 437-1869 x205
Cell: (315) 373-4081
Fax: (315) 437-1866
Email: <A class=moz-txt-link-abbreviated href="mailto:kingsleym@saic.com">kingsleym@saic.com</A>
-----Original Message-----
From: <A class=moz-txt-link-abbreviated href="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A>
[<A class=moz-txt-link-freetext href="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of eric wang
Sent: Monday, October 27, 2008 11:32 PM
To: <A class=moz-txt-link-abbreviated href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A>
Subject: [Bldg-sim] ERV with increasing cooling load
Hi,
I model a PSZ system with exhaust air heat recovery. I set the static
pressures of supply/exhaust fans as zero in ERV tab. Therefore, the fan
energy is the same with or without ERV. However, there is an increasing
cooling load in the cooling model. I changed the hourly report and
didn't find the reason. Any suggestions are highly appreciated.
Thanks
Shaojie
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