Most people don't realize how important it is to have their ducts cleaned. All the bacteria, dirt, and dust gets recycled throughout your house over and over again, and that's what you're breathing in. Breathing unclean air causes respiratory problems and other diseases. It's dangerous for your whole family.
Most companies use what is called negative pressure to clean out ducts, which basically vacuums all the dirt, debris, and other pollutants out of the ducts. The process works but if your air duct is long, and most are, the dirty air has to travel a long distance to escape the duct and isn't likely to get as clean. If you have bacteria in your system, you can't get rid of it unless you brush it clean and treat it. Make sure the company you use clean and sterilize the ducts.
Having your air ducts clean is not only important because of your health, but it will also prolong the life and efficiency of your air conditioning and heating system. If you have dirty ducts then dirt builds up on every part of the HVAC system. A dirt buildup on AC coils will increase your summer AC costs as much as 20%, and dirt and residue buildup on your gas furnace components can increase your risk of fire and carbon monoxide poisoning. Needless to say, it's dangerous all around.
When was the last time you had your air ducts clean? Having them cleaned once every few years can drastically improve the quality of your indoor air and most importantly, will keep you and your family healthy.