. I found a Vortex fan 4" and 6" that say they're 49 dBa's. Now, if you can find how loud that is for you, there's a starting point.
Refrigerator Humming 40 dBa
Normal Conversation 50-60 dBa
Vacuum Cleaner 70 dBa
This is misleading, don't get me wrong though the post is appreciated but it's not entirely accurate. The DBA listed on a fan like a Vortex rates the sound of the motor ONLY and NOT the sound of air rushing through a forced hole. A lot of these fans have quiet motors but there is nothing quiet about air rushing through a 4" or 6" hole.
That is why a refrigerator humming is 40 dBa sounds WAY quieter than a Vortex at 49 dBa... the refrigerator doesn't have a bunch of air rushing through it!!!
The Panasonic Whisper Fan sounds like the way to go but the post I'm quoting started in 2006 with updates in 2010. I mean, given how f*cking loud fans are for grow rooms... I'm really shocked this has not been better addressed.
I also think a Panasonic is 240v? THIS HAS BEEN AN ISSUE FOR ME FOR YEARS!! I need a quiet fan! Mad rep for anyone with some definitive information on this subject with proper sources. I'd *think* a reliable source has written up their thoughts on this, no?