Temperature Mapping

Temperature mapping is a comprehensive study in which multiple temperature sensors are placed at defined locations throughout a storage room, warehouse, trailer, or container to measure the temperature distribution over time and identify any hot spots, cold spots, or areas where temperature control is inconsistent. The results of the mapping study provide critical data for equipment qualification, storage location planning, and regulatory compliance.

A typical mapping study uses 9 to 30 calibrated temperature sensors placed in a three-dimensional grid pattern within the space being studied. The sensors record temperature at regular intervals, usually every 1 to 5 minutes, over a period of 24 to 72 hours. The study is conducted under loaded and unloaded conditions, with doors opening and closing to simulate normal operational use, and ideally during both summer and winter to capture seasonal extremes.

Findings and Applications

Temperature mapping studies commonly reveal that the area near dock doors experiences the widest temperature fluctuations, the space directly in front of evaporator fans may be significantly colder than the setpoint, corners and areas behind obstructions may be warmer than the rest of the space, and the temperature distribution changes when the space is loaded versus empty. These findings guide decisions about where to store the most temperature-sensitive products and where to place monitoring sensors for ongoing operations.

For regulatory purposes, temperature mapping is required or expected for pharmaceutical cold storage, validated shipping lanes, and facilities seeking third-party certification. The mapping data becomes part of the facility's qualification documentation and must be kept on file for regulatory inspection. Remapping should occur after any modifications to the refrigeration system, building envelope, or storage layout that could affect temperature distribution.