Data Centers | Design Guidelines | Informative | Telecommunication Spaces Data Center Design: Hot Aisle & Cold Aisle – Length and Width Requirements Efficient airflow management in data centers relies heavily on proper Hot Aisle and Cold Aisle configurations. To maintain thermal performance, equipment accessibility, and safety, it’s essential to follow key spatial guidelines. Aisle Length Guidelines Maximum Aisle Length: When equipment cabinets form a continuous row, the aisle length should not exceed 16 meters. Restricted Aisle Length: If one end of the aisle is closed off or lacks a personnel exit, the maximum aisle length should be limited to 6 meters for safe access and evacuation. Aisle Width Guidelines Hot Aisle Width : Minimum : 0.9 meters Recommended : 1.2 meters Cold Aisle Width : Raised Floor : Minimum 1.2 meters, allowing two full tiles between cabinet fronts for optimal airflow. Non-Raised Floor :• Minimum : 0.9 meters• Recommended : 1.2 meters Overhead Clearance Considerations For ceiling heights exceeding 3.7 meters, additional aisle width may be required to accommodate support lifts for accessing overhead systems such as lighting, fire detection, and suppression equipment. Proper aisle planning isn’t just about airflow—it’s about optimizing safety, serviceability, and system efficiency. By adhering to these length and width standards, data center designers can enhance operational reliability and cooling performance across all critical infrastructure.