While carbon filtration is the best solution for the chemical VOCs found in smoke, the particles of smoke will attract to one another as a result of charged hydrogen and oxygen molecules naturally found in the air. These charged molecules result from bi-polar ionization. The result is that these particles accumulate into larger sizes and become too heavy to float. You'll likely even notice smoke particles or ash accumulating on hard surfaces of your indoor spaces. Interestingly, this same effect occurs in nature--in the mountains, at the beach, and after a thunderstorm.