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Loik,<br>
<br>
Another thing to keep in mind is the heat that is "taken away from
the equipment" via exhaust.<br>
<br>
The heat generated by a piece of equipment can:<br>
-Be dissipated into the room<br>
-Be "taken away" by the cooling water.<br>
-Be "taken way" by exhaust.<br>
<br>
If a piece of equipment is not cooled and does not have exhaust then
all the heat gets dissipated into the room.<br>
<br>
If the piece of equipment is cooled and exhausted only part of the
heat generated will end up in the room.<br>
<br>
If you know how much heat is taken away by the cooling water and/or
exhaust that is great. If you do not, I saw engineers using factor
such as (PCW stands for process cooling water):<br>
100% of the power into the room if no PCW and no exhaust<br>
50% of the power into the room is no PCW but exhaust<br>
40% of the power into the room if PCW but no exhaust<br>
20% of the power into the room if both PCW and exhaust<br>
<br>
I prefer the "unique chiller (placed outside of the building)"
approach for cooling the equipment. If you can run the water from
the unique chiller directly through the equipment, you do not have
to deal with the heat generated by the "small chillers".<br>
<br>
Iulian<br>
<br>
<br>
<br>
<pre class="moz-signature" cols="72">iulian Codreanu, Ph.D.
Director of Operations, UD NanoFab
163 ISE Lab
221 Academy Street
Newark, DE 19716
302-831-2784
<a class="moz-txt-link-freetext" href="http://udnf.udel.edu">http://udnf.udel.edu</a></pre>
<div class="moz-cite-prefix">On 3/16/2015 10:36 AM, Loïk GENCE
wrote:<br>
</div>
<blockquote cite="mid:5506EA62.9000008@cetuc.puc-rio.br" type="cite">
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Hi Everyone,<br>
<br>
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>
Which is crucial here in Rio, where the average outside
temperature is of 30 deg C with a relative humidity of 75-80 %.<br>
<br>
I would like to have your help and/or comments on several points:<br>
<br>
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>
<br>
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>
<b> </b><b><br>
</b><b> - Is it reasonable for dimensioning the ACS cooling
power ? </b><br>
<br>
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>
<br>
<b> - Should I subtract from the </b><b>ACS cooling power</b><b>
value, </b><b> the cooling po</b><b>wer </b><b>from the
chillers?</b><br>
<br>
- <b>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>
<br>
<br>
I thank you very much for your kind help or comments.<br>
<br>
<br>
regards,<br>
<br>
Loïk.<br>
<br>
<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>
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