what size exhaust fan would i need?

I have my office that is 75m3 in size, it has many computer and electronic equipment that make it damn hot.
I have got 2 windows in the place opposite each other across the room. I have put a fan in the window to suck the hot air out and cold air in through the other outside window, this works fairly well but the fan is very noisy.
thinking of putting an inline fan in the ceiling with a vent or 2 in the middle of the room to suck the hot air out and cool air in through the windows. the fan would be a 150mm fan with 150mm vents and would need about 3m of ducting on it.
what size inline fan would I need?? 520m3/h be enough or not?
TT Mixflow In Line Fan 150mm w/ Lead & Plug | Pure Ventilation


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