I
think the unanswered question you're referring to is mine. We were trying to
simulate Trane Self-Contained Air handlers (SWUDs). McQuay and Carrier also
make these systems. You may not be referring to this type of system. SWUDs use
an internal economizer on floor's air handler which uses condenser water when OA
Temp drops below a certain setpoint. The waterside economizer option in DOE 2.2
is not the same as the SWUD system, I think. I believe this can be simulated
with equest using a seperate cooling tower and an add-on indirect evaporative
cooler. <br><div dir="ltr" align="left"><span><font face="Arial" size="2"><br>In real life the WSE is controled by condenser water
temperature. In DOE 2.2 I believe the control temperature a constant user
specified limit. </font></span></div>
<div> </div>
<span></span><font face="Arial"><font size="2">W<span>e never
finished the model we were working on so I'm not sure how to control
the cooling tower. Real SWUDs tie into the building's condenser water
loop. So I assume you can use the same schedule on the evaporative
cooler's cooling tower as the CT for the DX systems. Another energy
firm modeled the building and we did the base building design. We are
new to energy modeling so every meeting we had with the Architect and
other design personnel we would pick the modelers' brains as to how
they modeled these systems. Please let me know when you get the final
model to work.<br>
<br>DG<br></span></font></font><font face="Arial"><font size="2"><span></span></font></font><div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Xu,
Xiaowei<br><b>Sent:</b> Thursday, April 24, 2008 3:06 PM<br><b>To:</b>
<a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br><b>Subject:</b> [Bldg-sim] Water-Side
Economizer<br></font><br></div>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">Hi,</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">I have
some questions about the Water-Side Economizer simulation in eQUEST. I searched
for this topic in the simulation group archive. It seems that someone also had
the problems with the simulation of water-side economizer but no one answered
it. </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;"> </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">Currently I am working with an office building with DX
coil system. The proposed design uses the water side economizer because the
air-side economizer is not available. I added the water side economizer into the
existing condenser water loop. But the simulated result showed the system with
water-side economizer had more energy consumption than the system w/o economizer
because of more energy consumed by the fan, pump and cooling
tower.</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;"> </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">Here is
question about the simulations setting in eQUEST for water-side
economizer:</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">1. what
loop should the water-side economizer be attached to: the current existing
condenser water loop or a new condenser water loop?
</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">I tried
both and got quite different results. None of them saved
energy.</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">2. what
temperature in eQUEST should be used for control the water economizer? If the
current existing condenser water loop is used, how to control the temperature
both for the water-side economizer and the DX coil?</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">3. How
to set the control for the cooling tower? </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;"> </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">Any
suggestion would be much appreciated. </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;"> </span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;">Thanks.</span></font></p>
<p><font face="Arial" size="2"><span style="font-size: 10pt;"> </span></font></p>
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