Fan recommendation

I am in the process of building a 6x6x7ft grow room and I am looking for a fan recommendation. I will have two 400w hps lights and the fan will vent outside (dryer style vent). My only requirement is that it is quiet. The room is in the basement (1/2 surrounded by concert 1/2 drywall). Help pls....

we use the inline fans but theyre expensive but def the quietest. maybe try computer coaxial fans theyre cheap and quiet but ull need alot to vent ur room out.

Im looking at a vortex 4in 172 cfm fan. It says 4 sones but I have no idea what that sounds like.