could you explain why this is wrong.to me it makes perfect sence,the slower the air moves through the charcoal the more impurities get scrubed from the air. the faster the air passes through the charcoal the less time the charcoal is in contact with the contaminated air and inturn less oudor gets removed.
sorry for the delay.
Activated carbon is a mechanical filtration structure with a chemical adsorption surface. The molecules pass through the very porous material and certain molecules fix themselves within. You will have a rated capacity (not necessarily what is advertised) that will decrease with time as adsorption sites decline and the filter becomes clogged.
The capacity is a function of the mechanical filtration properties, not the chemical, which requires virtually no dwell time. You can 'over-blow' the filter, which will cause the filtered fluid (in this case, extracted air) to bypass the carbon particles (this is possible in some filters, depending on the medium packing structure)
My recommendation is to use your nose. It knows.
Many/most commercial AC filters can be opened up (you may need to drill out rivets and use a rivet gun to close it back up) and the AC 're-activated.' Be sure to replace the pre-filter (best) or thoroughly wash it. The quality of your pre-filter is very important to the long-term effectiveness of the filter.