Hey, I'm wondering the same thought ! 158 cfm / 10.52 mmH20. Seems like a good fan for the purpose.
I bought this fan. It works just ok with a hepa filter (for allergies) on it. I didn't actually end up using it on a carbon filter though. I bought a hon&guan 5" to use with the carbon filter in the end...
If you harass me in May (when my current grow is over) I can see if I can rig it to carbon filter to it and then I can report back on performance