Last Christmas while my family was opening gifts, I noticed strange dust particles coming from the floor air vents. I wasn’t too concerned about this since our furnace had been running on high for the past few days. I took a look at my furnace just in case and didn’t find anything wrong with it. I went online to an HVAC website and did some research to find out what was wrong with my furnace. I ignored the dust coming from the air vents for a few more days, but it got so bad that I couldn’t stand the poor air quality any longer. I called the HVAC company and scheduled a time for a furnace and air conditioning service man to come do a furnace check up. When the service man came, he told me the problem was coming from the super heater inside the furnace. He explained that the oil that the super heater was burning was dirty and causing soot build up in the air vents. Then when the furnace blew heated air through the vents it would bring soot particles with it. He took a metal wire brush and scrubbed my entire air duct system clean. Then he used a vacuum to get the soot out of the furnace vents. When the HVAC serviceman was finished, he scheduled two more appointments for that year to ensure the no more soot builds up in the furnace vents. Since this experience, I have had no problem with either my furnace or my air conditioning systems and I make sure the HVAC serviceman has several air vent cleanings a year.