Is using a wall cavity for a return in air conditioning systems acceptable?

Using a wall cavity for a return in air conditioning systems is acceptable in certain contexts. This practice can allow for efficient air circulation while utilizing space that might otherwise be wasted. A wall cavity can facilitate the return airflow needed to maintain balanced pressure and enhance the performance of the HVAC system, as long as it meets design and building code requirements.

However, for this to be effective and appropriate, the cavity must be properly sized, sealed, and connected to ensure that it does not create additional noise or airflow issues. It’s also essential for the cavity to be free from obstructions and contaminants that could affect air quality. Therefore, under the right conditions, using a wall cavity can be a practical and functional solution, justifying why it is marked as acceptable in this context.