Definition: The time required to reduce product temperature from initial temperature to target storage temperature. Also called “cool-down time” or “freeze-down time.”
Typical Pull-Down Times:
- Chilled products (+15°C to +4°C): 2-4 hours
- Standard freezing (+15°C to -18°C): 6-24 hours
- Blast freezing (+15°C to -18°C): 2-8 hours
- Deep freezing (-18°C to -35°C): 4-12 hours
Why It Matters:
- Long pull-down times risk product quality degradation
- Equipment capacity must be adequate for required pull-down time
- Pre-cooling/pre-freezing product before loading reduces transport refrigeration load
Related Terms: Cooling Capacity, Thermal Mass, Blast Freezing