[grahamwatson]

Hello everyone!

I am required to do some calculations in order to source the best fan/filter kit for a cabinet. I have already used about 5 different methods, the main ones are software such as Rittal Therm and Hoffman Calculator, all are giving different reuslts.

The problem I believe is with such little inputs they all use different factors to account for unknown geometric constraints based on experiments they have done.

The constraints I have to work with are:

Dimensions: 2100mm (H) x 800mm (W) x 1000mm (D)
Location: Within a suite free standing (therefore sides and bottom are restricted from heat transfer)
Total heat Power Inside: 1475W
Outside Temperature: 25C
Desired Inside Temperature: 35C

So far it appears all solutions are based around this equation:

CFM = k x P(W) / DeltaT

Where k is a factor that changes every time i find the equation and no one has really explained where it comes from.

Unfortunately for me this is not acceptable and I am asked to solve this without using unexplained factors. Can it be done?

I have been told "you have 1475W of heat, you have 25C coming in and 35C going out, what volumetric flow rate of air is required to achieve this?"

I would greatly appreciate any help someone could give me!

Kind Regards,
Graham