Air Systems Cleaning Specialist (ASCS) Practice Exam

If there are leaks in the supply ductwork of a residential HVAC system located in an attic, this will MOST likely cause what?

1. Positive pressurization of the occupied space

2. Balanced pressurization of the occupied space

3. Negative pressurization of the occupied space

4. Cleaner air for the occupied space

The correct answer is: Negative pressurization of the occupied space

Leaks in the supply ductwork of a residential HVAC system located in an attic primarily disrupt the airflow intended for the living areas of the home. When there are leaks, supply air can escape into unconditioned spaces, such as the attic, and not reach the intended rooms. This loss of air pressure can lead to a situation where the air pressure inside the living space becomes lower than the outside pressure, resulting in negative pressurization. Negative pressurization in residential spaces can cause several issues, such as drawing in unfiltered air from outside or from adjoining spaces, which may lead to decreased indoor air quality. Additionally, it can affect the thermal comfort of the space, as systems may struggle to maintain temperature due to inadequate airflow reaching the occupied areas. Hence, understanding the effects of ductwork leaks is critical for maintaining effective HVAC performance and ensuring a healthy living environment.