You need a carbon filter (or ozone generator) if your growing weed, end of!
If your concerned about noise then get one of these.
http://www.ebay.co.uk/itm/4-inch-duct-silencer-4-150mm-duct-silencer-hydroponics-600mm-long-/250922811327?pt=UK_HomeGarden_Garden_PlantsSeedsBulbs_JN&hash=item3a6c2a3fbf#ht_517wt_952
Or if you are in the U.S
http://www.ebay.com/itm/4-Inch-Inline-Muffler-Noise-Reducer-Silencer-Duct-Fan-Blower-Carbon-Filter-/160717947847?pt=LH_DefaultDomain_0&hash=item256b8943c7#ht_1842wt_1185
Ona is a good product but it doesn't neutralise odors like it claims it only masks them.
This is a plant I have vegging in my wardrobe at the moment, it is here until I take it to my grow site that is in another city.
It only stands 10" above a 9 litre pot.
It can be smelled from my front door (as soon as you walk into the house) and I've had to put a tub of "Ona Gel Pro" at the bottom of my stairs to avoid suspicion, even so my Girlfriend can STILL smell it over the Ona (she has a finicky nose).
The reason I can't smell it but she can is due to something called "Olfactory Fatigue", the science behind this I'll try to explain.
"
Have you ever noticed a particular scent upon entering a room, and then not noticed it ten minutes later? This is due to olfactory fatigue. The olfactory sense is unique because it relies on mass, not energy to trigger action potentials. Your ears do not "stop" hearing a sound after a certain period of time, nor do your eyes stop seeing something you may be staring at. This is because both the ears and the eyes rely on energy to trigger them, not mass. In the nose, once a molecule has triggered a response, it must be disposed of and this takes time. If a molecule comes along too quickly, there is no place for it on the olfactory hairs, so it cannot be perceived. To avoid olfactory fatigue, rabbits have flaps of skin that open and close within the nostrils. This allows for short, quick sniffs and lets the rabbit "keep in close odor contact with its environment." When we wish to fully perceive a scent, we humans also smell in quick, short sniffs, often moving the source of the smell in front of one nostril then the other. This behavior also prevents odor fatigue." (Stoddard & Whitfield, 1984)
You can also study this wiki on the subject.
http://en.wikipedia.org/wiki/Olfactory_fatigue
Ever heard the phrase "A pig can't smell it's own shit"? Well now you know where it comes from!
A carbon filter actually filters the offending odor molecules from the air and an ozone generator neutralises them.
NOTHING else will get rid of the smell, it will only mask it!
