Borzki,
My personal opinion is , you are not able to properly analyze the system ( pl. don't take my comment in any negative way)as this is not a conventional way of analysis and in opinion uncalled for.You have to understand the way the air cooler will behave. A mathematical model which is away from the physics of the problem will only require such unconventional analysis.
Pl. show it to your senior in your company and ask for his/her comments suggestions.
Regards
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anindya