[labnetwork] Thermal load in cleanrooms ISO 5/6

[Loïk GENCE]

Thank you all for your messages. It helps!

I'll introduced ligthning and FF units in the thermal load calculation.
I can see that the /a priori/ estimation of the diversity factor seems 
to be difficult.
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...

Thanks again!

Loïk.


On 16/03/2015 12:55, Mike Young wrote:
> Hi, Loïk. Welcome to the group.
>
> 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.
>
> 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.
>
> Good luck!
>
> --Mike
>
>
>> On Mar 16, 2015, at 10:36 AM, Loïk GENCE <Loik.gence at cetuc.puc-rio.br 
>> <mailto:Loik.gence at cetuc.puc-rio.br>> wrote:
>>
>> Hi Everyone,
>>
>> 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,
>> Which is crucial here in Rio, where the average outside temperature 
>> is of 30 deg C with a relative humidity of 75-80 %.
>>
>> I would like to have your help and/or comments on several points:
>>
>> 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)?
>>
>> 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.
>> ***
>> **        - Is it reasonable for dimensioning the ACS cooling power ? *
>>
>> 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.
>>
>> *        - Should I subtract from the **ACS cooling power**value, 
>> **the cooling po**wer **from the chillers?*
>>
>>         - *Do you think a central and unique chiller (placed outside 
>> of the building) is preferred to several smaller chillers placed 
>> closer to the equipment?*
>>
>>
>> I thank you very much for your kind help or comments.
>>
>>
>> regards,
>>
>> Loïk.
>>
>> -- 
>> __________________________________________
>> 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
>>
>> loik.gence at cetuc.puc-rio.br
>> __________________________________________
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>
> -- 
> Michael P. Young         (574) 631-3268 (office)
> Nanofabrication Specialist                      (574) 631-4393 (fax)
> Department of Electrical Engineering            (765) 637-6302 (cell)
> University of Notre Dame mike.young at nd.edu <mailto:mike.young at nd.edu>
> B-38 Stinson-Remick Hall
> Notre Dame, IN 46556-5637
>

-- 
__________________________________________
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

               loik.gence at cetuc.puc-rio.br
__________________________________________

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