NADCA sets the standards for air duct cleaning companies. It is required that all members have one staff member who is a certified Air Systems Cleaning Specialist (ASCS). Its members have signed a Code of Ethics, and they have invested time and resources in training and educating its employees. Members must participate in continuing education and take regular recertification exams. In addition, NADCA members must meet specific insurance requirements. Lastly, cleaning and restoration of your heating and cooling system must be done in accordance to NADCA standards.