There is no way around it – growing plants stink. Unless you enjoy your house smelling like a barnyard, odor control is a must.
There are three basic approaches to odor control. The first and cheapest are products such as those made by Ona. These sprays or gels are not odor maskers, like incense or scented candles. They produce molecules that attract and attach to odor molecules, pulling them out of the air. They are very effective in lower odor situations, such as a clone or veg room.
Ozone generators are the next level. These electric machines generate ozone, which is made up of three oxygen atoms stuck together, rather than the two atoms of oxygen that we breathe. This third atom is very unstable and zips off to attach itself to any other convenient molecule (the stink) floating by. When it grabs on, the stinky molecule drops out of the atmosphere. Ozone is also a very effective sanitizer that will destroy mold, bacteria and other pathogens as well.
Ozone does have a distinctive odor, which dissipates quickly.
The most effective odor remover is the charcoal filter. These will remove 99% of the odor in your grow room if the humidity, temperature, and CFM (Cubic Feet per Minute) of the fan is met. Figure out the cubic feet of your room (length x width x height.) Your fan and filter should be able to move the entire volume of air in your room through the filter in less than three minutes.
For example, a 10x10x8 room is 800 cubic feet. A fan that, by itself, is rated for 396 cubic feet per minute (cfm) slows down when required to work harder through a filter. Read the cfm information on the filter, not the fan. The filter will usually recommend a fan size and speed.
You can also attach your outtake fan directly to the filter, duct it to your reflector, and then blow clean air over the lamp, pushing out heat as well.
All three of these methods can be used in any combination.