I have a Panamex brand that i purchase that is 0.4 sones for about $65. It is 70 cfm. If you do not know sone ratings then I will just tell you tha0.4 is not audible to the human ear unless you put your ear right up to it. I do not use it anymore, but when i did I would have to put my hand up to it to make sure it was still working. I also had it running through a carbon scrubber that I made. Honestly though I changed to a 4oo cfm inline with a regulator. I only use about half of the available cfm, b ut if I need more it is there. Also if I decide to go bigger or change my setup I have more cfm available. By the time it is all said and done I think the price difference was about $95 and that includes the power regulator. It is money well spent. The only thing you have to really know is that they inlines are going to be way louder then the Panamex exhaust fan. I had to insulate all of my ducting, and the fan itself and it is still louder. If your space is smaller then the Panamex would be great for you. It would even work for a 3 x 4 closet depending on the lighting setup. My two cents.