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This is the wrong way to look at evap cooling performance. In fact,
the whole logic of sizing using design conditions falls apart when
it comes to evap coolers. Evaporative cooling works by taking
advantage of the wet-bulb depression to trade off latent for
sensible heat. <br>
When the wet-bulb depression (DBT - WBT) is low or when the WBT is
high, evap cooling<br>
will provide little cooling. A better way to size evap cooling is
to either minimize the unmet<br>
cooling hours, or if there is an AC backup, maximize the energy
reductions.<br>
<br>
If you're working with a fixed evap cooling size, then you should
look at the number of unmet cooling hours to see the benefits of a
window upgrade, as well as the reduction (if any) of electricity
use.<br>
<br>
Joe<br>
<pre class="moz-signature" cols="90">Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
<a class="moz-txt-link-abbreviated" href="mailto:yjhuang@whiteboxtechnologies.com">yjhuang@whiteboxtechnologies.com</a>
<a class="moz-txt-link-abbreviated" href="http://www.whiteboxtechnologies.com">www.whiteboxtechnologies.com</a>
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"
</pre>
<br>
On 8/16/2011 1:11 PM, deepika khowal wrote:
<blockquote
cite="mid:CAHKrw7X731ceh362=1p=YmRXzAGUAL0=rG1Mh7s0ZRGkL8ZJsQ@mail.gmail.com"
type="cite"><br>
<div>This is an existing building with evaporative coolers.</div>
<div>the proposed design to upgrade the windows and check the
relative benefits.</div>
<div>I dont see much benefits in energy because evaporative
coolers are sized based on Cfm and not btus, the savings will be
in cfms.</div>
<div>correct me if I am wrong.</div>
<div>is there any other way I can show the benefit in the proposed
case if not HVAC benefits?</div>
<div>Thanks<br>
<br>
<div class="gmail_quote">On Tue, Aug 16, 2011 at 1:00 PM, Nick
Caton <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:ncaton@smithboucher.com">ncaton@smithboucher.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);">Hi Deepika,</span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);">I’m not certain any
increase/decrease in cooling loads (such as solar
loads affected by changing glazing) should have any
effect on the reported “space cooling energy” when
you’re using evaporative coolers. Direct
evaporative (swamp) coolers of the simplest sort
have only fan and pump energies to consider - no
refrigerant! I would advise looking up the Detailed
Simulation Reports Summary page 158/160 to review
end use categories and what they cover. </span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);">I am unfamiliar with
Bridgeport’s climate, but as a general rule if I
observed a significant amount of glazing in a space
served by a direct evaporative cooler… I’d be extra
cautious to ensure the HVAC designer is carefully
considering condensation and potential for other
humidity-driven issues along the way. I’m most used
to seeing them applied to well-ventilated and/or
open-air spaces such as garages and gyms/hangars.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);">~Nick</span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"><img
src="cid:part1.05050303.02060803@whiteboxtechnologies.com"
alt="cid:489575314@22072009-0ABB" width="119"
height="37"></span><b><span style="font-size:
11pt; color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt;
color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="color: rgb(45, 77,
94);">NICK CATON, P.E.</span></b><b><span
style="color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt;
color: rgb(204, 153, 0);">SENIOR ENGINEER</span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt;
color: rgb(204, 153, 0);"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt;
color: rgb(45, 77, 94);">Smith & Boucher
Engineers</span><span style="font-size: 7.5pt;
color: rgb(204, 153, 0);"></span></p>
<p class="MsoNormal"><span style="font-size: 10pt;
color: rgb(45, 77, 94);">25501 west valley parkway,
suite 200</span></p>
<p class="MsoNormal"><span style="font-size: 10pt;
color: rgb(45, 77, 94);">olathe, ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt;
color: rgb(45, 77, 94);">direct <a
moz-do-not-send="true" href="tel:913.344.0036"
value="+19133440036" target="_blank">913.344.0036</a></span></p>
<p class="MsoNormal"><span style="font-size: 10pt;
color: rgb(45, 77, 94);">fax <a
moz-do-not-send="true" href="tel:913.345.0617"
value="+19133450617" target="_blank">913.345.0617</a></span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"><a moz-do-not-send="true"
href="http://www.smithboucher.com"
title="blocked::www.smithboucher.com"
target="_blank"><span style="font-size: 10pt;
color: blue;">www.smithboucher.com</span></a></span><u><span
style="font-size: 10pt; color: blue;"> </span></u><span
style="font-size: 11pt; color: rgb(31, 73, 125);"></span></p>
<p class="MsoNormal"><span style="font-size: 11pt;
color: rgb(31, 73, 125);"> </span></p>
<div style="border-right: medium none; border-width: 1pt
medium medium; border-style: solid none none;
border-color: rgb(181, 196, 223) -moz-use-text-color
-moz-use-text-color; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span
style="font-size: 10pt;"> <a
moz-do-not-send="true"
href="mailto:equest-users-bounces@lists.onebuilding.org"
target="_blank">equest-users-bounces@lists.onebuilding.org</a>
[mailto:<a moz-do-not-send="true"
href="mailto:equest-users-bounces@lists.onebuilding.org"
target="_blank">equest-users-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>deepika khowal<br>
<b>Sent:</b> Tuesday, August 16, 2011 1:36 PM<br>
<b>To:</b> <a moz-do-not-send="true"
href="mailto:equest-users@lists.onebuilding.org"
target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> [Equest-users] evaporative coolers
in equest</span></p>
</div>
<div>
<div class="h5">
<p class="MsoNormal"> </p>
<p class="MsoNormal">Hello all</p>
<div>
<p class="MsoNormal">I am modeling a building in
Bridgeport, CA which has evaporative coolers.</p>
</div>
<div>
<p class="MsoNormal">I dont see any benefits if I
replace existing clear glass with low-e in
cooling energy consumption.</p>
</div>
<div>
<p class="MsoNormal">Did anyone model evaporative
coolers/swamp coolers before?</p>
</div>
<div>
<p class="MsoNormal">I want to know whether there
is a way to show cooling benefit with such HVAC
system.</p>
</div>
<div>
<p class="MsoNormal">Thanks</p>
</div>
<div>
<p class="MsoNormal">
Regards</p>
</div>
<div>
<p class="MsoNormal">Deepika</p>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
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