Not just that, but the mere fan vibration is enough to make ISS unsuitable for some particularily sensitive 0g experiments. There was an entire co-orbital modul

Not just that, but the mere fan vibration is enough to make ISS unsuitable for some particularily sensitive 0g experiments. There was an entire co-orbital module for ISS in the plans (that never came to fruition, sadly) to provide the station with a separate volume with high-quality microgravity, that would be in the same orbit, docking with the station from time to time.