Being spared a fan with its noise is the exact reason that I use an MBA. I surely do not want to retrofit a fan. But nice idea anyways to look after your cooling approach.
Frore systems claims 21 dBA. That's about the level in a quiet area in nature without wind. Much less then even a whisper. Unless you are sitting in an extremely quiet room you won't hear it.
Generally it won't spare you of the noise, as the exit velocity of the stream will be quite a bit higher, which will result in a higher pitch, which is quite a bit more noticeable due to the quirks of human hearing.
it doesn't use a fan
Video says it expels air, generating sound at about 25 db, so not much "air noise".