A data storage and retrieval system such as a robotic library has a large plurality of removable storage media, such as tape cartridges, for purposes of I/O. To enhance performance and reliability of the library, a thermodynamic model of the library is constructed and stored in the library, and environmental conditions such as the temperature, humidity, and flow rate of cooling air coming into, flowing through, and leaving the library are monitored. The thermodynamic model of the library includes an acceptable operating range for the library in a psychrometric chart; and the product of the effective thermodynamic mass and specific heat of the library.