InterNACHI Heating, Ventilation, and Air Conditioning (HVAC) 2025 – 400 Free Practice Questions to Pass the Exam

In a scenario where there is one large return register located in the center hallway, checking to see if the bedroom doors are undercut at the bottom is the most appropriate first course of action. This is important because the effectiveness of a single return register in centralizing airflow relies heavily on how air circulates throughout the home.

When bedroom doors are tightly sealed without undercuts, they can restrict airflow to and from those rooms, which disrupts the intended return air pathway. Undercutting the doors allows the air to flow freely from the bedrooms back to the return register, enhancing the system's ability to regulate temperature evenly throughout the space. Ensuring that doors are properly designed for airflow is a fundamental step in optimizing the performance of the HVAC system.

Other options might be considered later on; for instance, recommending additional return ducts in each bedroom could be a valid solution if airflow issues persist, but it is essential to first assess the existing conditions affecting airflow. Reporting that the A/C system will not work well or that the life of the AC equipment will be reduced can be concerning, but without first determining the state of the airflow dynamics created by the door design, those assessments may be premature. Thus, starting with the condition of the doors helps establish a foundational understanding