Recognizing potential indoor air quality problems is the first step to resolving them. If you are having brown and black streaks of dirt buildup originating from your registers you need to investigate to find out where that dirt is coming from before spending money on duct cleaning.
If your ducts are dirty, you have a problem. Ducts don’t generate dirt, they only transfer dirt laden air from one place to another so finding the origin of the dirt and stopping that source is the real answer.
The most common areas that this dirt is coming from are:
Most air filters do very little air cleaning and they are not designed to clean the air. Air filters in HVAC systems are designed to protect the equipment from large debris, keep the fan in balance and not allow the evaporator coil to plug up. The large bits of debris you see building up on most air filters is not harmful to your lungs. It is the smaller size particulates that make it into the lungs.
Many filters are not the correct size or lack the correct cradle in which to sit in. After slipping that filter into your furnace you close the door and the first thing the filter does is pick up and let dirt laden air bypass it.
If your furnace required a 16 x 20 filter and a 14 x 19 or a 18 x 22 inch filter is installed the resulted filter air will not be complete.
Broken ducting can suck dirty air from outside the home, in the attic or crawl space, into the homes living area.
Gaps and unsealed connections in the plenums and ducting. Elbows and metal to metal connections leak airflow.
All air filters are rated as to their maximum airflow design speed. This measurement is in feet per minute. If the filter is great fitting, perfectly sealed, but too small, the velocity of the air traveling through that filter will be too fast. Air moving a greater velocity than the filter is designed to accept will pull the dirt right the filter not allowing it to load up with dirt. This will render the filter useless.
Failure to keep a clean filter increases the air velocity across those open parts of the filter and causes the filter to allow dirt to pass right through it.
The bottom line in keeping clean walls and ceiling where the registers are located is ensuring that your system is regularly maintained by a reputable company. Maintenance is not a 15 minute checkup. A properly maintained system with a good quality filter will never produce black streaks on your walls and ceilings.
Have them inspected and tested for leaks. We perform State Certified Duct Testing. Give us a call and we can help.