The air filter in your home is an important component of your HVAC system, and it's not normal for it to turn black. If you've noticed that your air filter is black instead of the usual gray layer of dust and dirt, there are a few possible causes. The air filter may be very clogged, which can restrict airflow and damage the HVAC system. Burning candles can also cause black soot to accumulate on the air filter, especially if you burn scented candles.
Lastly, mold growth in humid areas can cause the air filter to turn black. Soot is a by-product of burning candles, and it can cause our air filters to turn black quickly. Scented candles, especially, are often good culprits of black soot deposition because they contain more “impurities” that don't burn properly. To prevent this from happening, cut the candle wicks to a quarter of an inch before lighting them or try all-natural candles made from soy.
In Florida, air conditioning systems can provide the perfect habitat for mold growth. Mold can make you and your family seriously sick, so if you notice mold growth on air filters, dispose of them immediately and put them in fresh air filters. Failure to change air filters can restrict airflow, which decreases indoor air quality in the home and puts excessive pressure on the air conditioning system. Be sure to subscribe to the Filter King blog to learn more about air filters, air conditioning, and home improvement.
And, over time, soot accumulates on the surfaces of your home (walls, carpets, curtains, air filters, etc. When this happens, it means that you don't change the filter regularly, so the solution would be to set a set schedule to check your filter and change it to a new one.