Air Systems Cleaning Specialist (ASCS) Practice Exam

Using HEPA filters during duct cleaning is essential primarily because they are designed to trap a high percentage of small particles, including allergens, dust, and other contaminants that can negatively impact indoor air quality. HEPA stands for High-Efficiency Particulate Air, which means these filters can capture particles as small as 0.3 microns with an efficiency of 99.97%.

When duct cleaning is performed, the process can stir up many particles that have settled in the air ducts. Without HEPA filters, these particles could be released back into the air, defeating the purpose of cleaning. By utilizing HEPA filters, the process not only cleans the ducts but also ensures that the air being recirculated within the building is significantly cleaner, leading to improved respiratory health for occupants. This is particularly important in environments where individuals suffer from allergies or asthma, as reducing airborne contaminants can mitigate their symptoms and contribute to better overall indoor air quality.

The other options do not directly relate to the primary function of HEPA filters during duct cleaning. While factors such as energy efficiency and humidity levels may be relevant in broader HVAC considerations, they are not the primary focus when it comes to using HEPA filters specifically.