Air Systems Cleaning Specialist (ASCS) Practice Exam

The typical cleaning sequence of an HVAC system is performed in the order of exhaust, air handler, return, and then supply to ensure effective removal of accumulated contaminants and to maintain optimal system performance.

Beginning with the exhaust ducts allows for the elimination of pollutants that have already left the conditioned space. This helps in preventing the reintroduction of these contaminants back into the system. Following this, cleaning the air handler is crucial since it contains components like filters and coils that can collect dust and debris. This step ensures that the air handler functions efficiently and does not contribute to poor indoor air quality.

Next, moving to the return ducts helps to clear out any dust and particulate matter that may have built up as air is pulled into the system. Cleaning these ducts prepares them to carry clean air into the system effectively. Finally, the supply ducts are cleaned, which is vital for maintaining the cleanliness of the air that is delivered into the living space.

This comprehensive order enhances the efficiency of the cleaning process by preventing cross-contamination and optimizing airflow throughout the system.