What describes front-to-back airflow in data centers?

• A. Air flows from hot aisle toward cold aisle.
• B. Air is recirculated within cabinets without directional bias.
• C. Standard DC airflow direction: cool air pulled from cold aisle, exhausted to hot aisle.
• D. Airflow direction is not standardized in data centers.

Answer: (C)

Front-to-back airflow means air enters the rack from the front, where the equipment draws in cool air, and exits the back as warmer air. In the standard data-center setup, cold air is supplied into the cold aisle in front of the racks and pulled into the servers, then expelled into the hot aisle at the back. This matches the description that cool air is pulled from the cold aisle and exhausted to the hot aisle. Air flowing from hot toward cold would be back-to-front and can create hotspots; recirculation without a defined path lacks the intended intake/exhaust flow; and saying airflow direction isn’t standardized ignores the common cold-aisle/hot-aisle design used in most facilities.