Forced-Air Cooling for Fresh Produce

Forced-air cooling uses fans to create a pressure difference across pallets or cartons so refrigerated air moves through package vents and across the product. A cold room by itself does not guarantee rapid product cooling: if air bypasses the load, the room sensor may reach setpoint while the commodity remains warm.

WHEN FORCED AIR FITS
Forced air is commonly used for packed berries, peaches and many vegetables that are not suited to direct water contact. Commodity tolerance, package strength, vent area, stack pattern, humidity and the required cooling window must all be checked before selecting the method.

HOW THE AIR PATH WORKS
A fan and plenum create lower pressure on one side of the load. Tarps, pallet covers or seals close bypass paths so air is pulled through aligned carton vents, through the product and into the plenum. Gaps, blocked vents and misaligned cartons raise resistance or let air travel around the product.

WHAT 5 STAR ASKS BEFORE SIZING
• Commodity, cultivar and package style.
• Pounds or pallets per cooling cycle and per hour.
• Entering pulp temperature, target temperature and allowed cooling time.
• Carton vent area, stack pattern and pallet dimensions.
• Room temperature, relative-humidity needs and product moisture-loss sensitivity.
• Fan airflow, static pressure, evaporator capacity, defrost strategy and simultaneous loads.
• Sanitation, condensate drainage, controls, redundancy and future expansion.

VERIFY PRODUCT TEMPERATURE
Measure representative pulp temperatures at the warmest expected locations in the load. The 7/8 cooling point can be used as a performance benchmark, but it is not a universal final holding temperature. Room-air readings alone do not prove the center of the load is cooled.

COMMON DESIGN MISSES
Undersized refrigeration capacity, fans selected without the package pressure drop, unsealed pallet gaps, weak cartons, blocked vents, uneven loading and no repeatable temperature-verification plan can all extend cooling time and produce inconsistent results.

DISCUSS YOUR APPLICATION
5 Star Refrigeration Division designs, installs, services and maintains post-harvest cooling systems for growers, packers and processors across Georgia and the Southeast. Bring your commodity, package, throughput, entering temperature and target cooling window to the project conversation.

Sources & Further Reading: NC State Extension, Forced-Air Cooling; UGA Cooperative Extension publications on blueberries, blackberries and peach handling. Last reviewed: August 2026.