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Thank you all for your messages. It helps!<br>
<br>
I'll introduced ligthning and FF units in the thermal load
calculation.<br>
I can see that the <i>a priori</i> estimation of the diversity
factor seems to be difficult.<br>
Overestimating the thermal load is comfortable, but, here, I really
have to minimize the cost of the HVAC system choosing a proper
size/power of the HVAC because of our limited budget...<br>
<br>
Thanks again!<br>
<br>
Loïk.<br>
<br>
<br>
<div class="moz-cite-prefix">On 16/03/2015 12:55, Mike Young wrote:<br>
</div>
<blockquote cite="mid:A2C906E2-EE44-4331-AA45-FB87D4DD12F1@nd.edu"
type="cite">
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Hi, Loïk. Welcome to the group.
<div class=""><br class="">
</div>
<div class="">I would caution you about neglecting the heat
contribution of the cleanroom lighting and the fan filter units.
Make sure they are really, truly, negligible, because it is not
difficult for them to dominate the total cleanroom heat load
under some conditions! In addition, we find that almost all of
our equipment is in operation almost all of the time, so before
you use the .75 diversity factor, make sure it is realistic.</div>
<div class=""><br class="">
</div>
<div class="">The ACS has to be designed to meet the worst-case
heat load, which will be worst-case weather conditions, plus
everything turned on and running, plus maximum personnel heat
load, under conditions of worst-case (maximum) makeup air flow.
Getting all of this right is one of the most challenging
problems in cleanroom design.</div>
<div class=""><br class="">
</div>
<div class="">Good luck!</div>
<div class=""><br class="">
</div>
<div class="">--Mike</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
<div>
<blockquote type="cite" class="">
<div class="">On Mar 16, 2015, at 10:36 AM, Loïk GENCE <<a
moz-do-not-send="true"
href="mailto:Loik.gence@cetuc.puc-rio.br" class="">Loik.gence@cetuc.puc-rio.br</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
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http-equiv="Content-Type" class="">
<div text="#000000" bgcolor="#FFFFFF" class=""> Hi
Everyone,<br class="">
<br class="">
I am working on the design of a small cleanroom facility
(70m2) ISO 5/6. Right now, I am dealing with the problem
of thermal load,<br class="">
Which is crucial here in Rio, where the average outside
temperature is of 30 deg C with a relative humidity of
75-80 %.<br class="">
<br class="">
I would like to have your help and/or comments on
several points:<br class="">
<br class="">
Most of the manufacturers do not provide a value for the
thermal load (why?). Assuming 2 or max 3 people working
simultaneously in the cleanrooms, and usual cleanroom
value: 22 deg C - 55% humidity. The main issue is: how
can I estimate the cooling power required for the Air
Conditioning System (ACS)?<br class="">
<br class="">
I have the list of equipments we'll have and the
corresponding electrical power. I assumed the heat
generated by 2 users and added the total electrical
power dissipated as heat inside of the cleanroom, using
a simultaneity factor of 0.75 (all equipments won't be
turned on at the same time) and neglected the heat
produced by the filter fan and lightning. <br class="">
<b class=""> </b><b class=""><br class="">
</b><b class=""> - Is it reasonable for
dimensioning the ACS cooling power ? </b><br class="">
<br class="">
Also most of the equipments have a cooling water
circuit. But the cooling power needed is well described
in the installation manual provided with the equipments.
<br class="">
<br class="">
<b class=""> - Should I subtract from the </b><b
class="">ACS cooling power</b><b class=""> value, </b><b
class=""> the cooling po</b><b class="">wer </b><b
class="">from the chillers?</b><br class="">
<br class="">
- <b class="">Do you think a central and unique
chiller (placed outside of the building) is preferred
to several smaller chillers placed closer to the
equipment?</b><br class="">
<br class="">
<br class="">
I thank you very much for your kind help or comments.<br
class="">
<br class="">
<br class="">
regards,<br class="">
<br class="">
Loïk.<br class="">
<br class="">
<pre class="moz-signature" cols="72">--
__________________________________________
Dr. Loïk Gence
PUC-RIO/CETUC-LABSEM
End Rua Marques de São Vicente, 225-Gavea
CEP:22451-900 Rio de Janeiro, RJ-Brasil
(Telefone) +55 (021) 3527-2193
(Mobile) +55 (021) 99156-5558
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:loik.gence@cetuc.puc-rio.br">loik.gence@cetuc.puc-rio.br</a>
__________________________________________</pre>
</div>
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</blockquote>
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<br class="">
<div apple-content-edited="true" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal;
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-webkit-line-break: after-white-space;" class="">-- <br
class="">
<font class="" face="Consolas"><span style="font-size:
11px;" class="">Michael P. Young
(574) 631-3268 (office)<br class="">
Nanofabrication Specialist (574)
631-4393 (fax)<br class="">
Department of Electrical Engineering (765)
637-6302 (cell)<br class="">
University of Notre Dame <a
moz-do-not-send="true" href="mailto:mike.young@nd.edu"
class="">mike.young@nd.edu</a><br class="">
B-38 Stinson-Remick Hall<br class="">
Notre Dame, IN 46556-5637</span></font></div>
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<br class="">
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
__________________________________________
Dr. Loïk Gence
LABSEM – PUC-RIO
End Rua Marques de São Vicente, 225-Gávea
CEP:22451-900 – Rio de Janeiro, RJ-Brasil
(Telefone) +55 (021) 3527-2193
(Mobile) +55 (021) 99156 5558
<a class="moz-txt-link-abbreviated" href="mailto:loik.gence@cetuc.puc-rio.br">loik.gence@cetuc.puc-rio.br</a>
__________________________________________</pre>
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