Definition: Temperature variation within a refrigerated space or vehicle, typically measured as the difference between warmest and coldest locations.
Acceptable Gradients:
- Well-designed cold room: ±1-2°C throughout space
- Transport vehicles: ±3-5°C (front to rear)
- Poorly designed systems: ±10°C+ (unacceptable)
Why It Matters:
- Large gradients indicate poor air circulation or insufficient capacity
- Products in warm zones may exceed temperature limits even if controller shows acceptable average
- Temperature mapping identifies gradient problems
Causes:
- Inadequate airflow or fan capacity
- Blocked air returns or supply vents
- Undersized refrigeration system
- Poor load stacking (blocking airflow)
- Multiple door openings
Related Terms: Temperature Mapping, Hotspots, Cold Spots, Air Circulation