Are undercut doors allowed for return air movement?

Undercut doors are indeed permitted for return air movement, as they can effectively facilitate air flow between spaces while maintaining a clean aesthetic. The design of an undercut door allows for a gap at the bottom, which enables air to pass from the conditioned space back to the air handling unit. This is crucial for ensuring proper ventilation and air circulation in a building's HVAC system.

The North Carolina Mechanical Code allows this practice because undercut doors can improve system efficiency and reduce pressure imbalances in a building. However, it's important to follow guidelines regarding the size of the undercut to ensure that it meets the requirements for airflow, as excessively large openings could lead to drafts or unfiltered air transfer.

In residential and commercial settings, using undercut doors can benefit both the appearance and functionality of the HVAC system when installed and sized correctly.