How many separate return-air intakes must be installed on each level of a multi-level structure?

In a multi-level structure, having at least one separate return-air intake on each level is essential for maintaining proper airflow and ensuring efficient heating, ventilation, and air conditioning (HVAC) system operation. This requirement supports effective air circulation and helps balance the air pressure within the building, which is crucial for comfort and efficiency.

When there is only one return-air intake on a level, it may lead to inadequate air circulation, causing temperature imbalances, drafts, or even stale air in some areas. With at least one designated return-air intake on each level, the HVAC system can efficiently draw in air from various parts of that level, enhancing air quality and overall system performance.

In summary, installing one return-air intake on each level is a crucial design and installation practice that ensures reliable and adequate ventilation throughout a multi-level building, promoting comfort and energy efficiency.