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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">
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<div><span class="543091215-28102008"><font color="#0000ff"
face="Arial" 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 color="#0000ff"
face="Arial" 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>
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<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="border-left: 2px solid rgb(16, 16, 255); padding-left: 5px; margin-left: 5px;">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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