Each time when fan is working, they get into your respiration. American Lung Association and other medical authorities verified that air’s quality indoors is the major cause of allergy and respiratory diseases. Allergy specialists recommend air ducts cleaning in order to alleviate symptoms for patients suffering from asthma and allergy. Content of hazardous building materials and sheetrock dust in air duct systems was found even in newly constructed houses. Debris, dust and dirt build up in your HVAC system. This makes the system less efficient, which means it has to run for longer periods of time to get the same results. This can put a lot of strain on the blower motor and a shorter life span for the components of your HVAC system. Besides, your bills will go up if your system runs a lot. Dust can clog different components and keep them from working properly. Your furnace and central air conditioning system circulates air all over your house or office. This also provides circulation of dust filaments and other impurities that exist in any house or office. Some of these impurities settle inside pipelines accumulating formation of a thickening layer, which constantly pollutes air indoors.