Carbon and HEPA filters are very effective and efficient at removing the smell of marijuana smoke while cleaning the air of smoke particulates. HEPA stands for high-efficiency particulate air.
True HEPA is the most effective particulate filtering material on the market, made from very fine paper (not synthetic materials). Unlike electrostatic precipitators or air filters that use negative ions, a HEPA filter can actually intercept and trap unbelievably small particulates which allow the air to remain clean without the creation of harmful byproducts. A medical grade HEPA air purifier will clean the smoke particulate you can see, but more importantly, it can help eradicate the particles that you can't!
Austin Air purifiers also combat weed smoke by employing an active carbon filter. Activated carbon is produced by exposing a source of carbon to extreme heat, causing it to become more porous and increasing its surface area. One tiny piece of activated carbon has so many pores that the surface area may be larger than a regulation football field. The porous surface of activated carbon works to absorb odors and chemicals as air passes through it.
Below are some of the best air filters which can remove cannabis odor as well as clean the air.