Not sure what size fan and filter to get....

I have a 12'x6'x7' enclosed room w/ 20 pots, I plan on getting a HEPA and carbon filter with an inline fan to scrub the air. What size do you suggest for that size room and any good suggestions?

Also is there a way to make those inline fans queit? I plugged in the 6" one I plan on using for my lights and it was just too loud. I will be using a thermostatic variable fan speed controller so the fan speed changes with temp difference so the fan isn't always on full blast, but are there any products out there to queit these inline fans down? thank you

Well you have a total volume of just over 500 cubic feet, so any fan that can exchange that volume in 5 min or less. The smallest fan you could use would be 100cfm and same with the filter. I would suggest going with a filter a bit larger (higher cfm rating) than the fan. Because a 100cfm fan will not flow 100cfm with the filter in place, doesn't matter if your pushing or pulling. I would go with a filter rated for 125-150 cfm. Also remember these are the minimum numbers.

If you intend to build your own filter I highly recommend going to a manufacturers website to get specifications for the size of the filter and the amount of activated charcoal you will need. For example, lets say you were going to build a 100cfm filter. If the manufactured filter is 1' square 6" thick and weighs 15lbs, than your home built filter should be too.

If you already tried suspending your fan from ropes or bungee cords and its still not quiet enough, try boxing it up. Build a box out of plywood or MDF just big enough for the fan to fit in, couple holes the same size as the inlet/outlet and then pack in some fiberglass insulation. I've seen people use that expanding foam insulation too, but I think the batton insulation would have better sound damping.

Hope this helps..........

Is this a centrifugal fan (Can fan, etc)? If so, the speed controller should lessen the noise substantially at lower speeds. But if you have to run it closer to the top end, possibly an inline duct muffler would help? If you could run a larger diameter duct, you could afford to run a larger fan at lower rpms for the same cfm, assuming the run is not too long.

Where can I find a speed controller with a thermostat like yours?

Funkadelic