The purpose of ventilation system in every house is air recycling. We need it to breathe easily and to feel good respectively. When the HVAC system heavily contaminated, the air quality is noticeably reduced. As a result we feel uncomfortable, tired and unproductive. Add to this unpleasant smell and energy losses (ventilation system consumes more electricity for work), and you will understand the necessity of air duct cleaning.
For prevention of respiratory diseases and other problems, you should check and clean your ventilation system at least one time a year. But first you may ask the question about how does duct cleaning work carried out and what you need to do. And the thing is that you don't have to do anything! What does it mean? There are special services for professional air duct, dryer vent and chimney cleaning. Yes, the companies like us.