A reefer container is a refrigerated shipping container equipped with its own integrated cooling and heating unit, used to transport temperature-sensitive cargo such as food, flowers, and pharmaceuticals. Unlike a standard dry container, a reefer maintains a precise, set temperature throughout the journey as long as it is supplied with power.
For a market like Miami, a top U.S. gateway for produce, seafood, and perishables from Latin America, reefer containers are the backbone of the cold chain that keeps imported food safe from origin to store shelf.
How does a reefer container work?
A reefer is essentially a large, insulated box with a built-in refrigeration unit at one end. It draws power from the ship’s grid at sea, from terminal “reefer plugs” at the port, and from a diesel generator (a “genset”) clipped onto the chassis during road transport. Air is circulated through a T-bar floor and around the cargo to hold a uniform temperature. Operators set the temperature, and many units also control humidity and fresh-air exchange for living produce that continues to respire.
Reefer container sizes and temperature range
- Sizes: Most reefers are 20-foot or 40-foot high-cube units, with the 40-foot high-cube being the most common for ocean trade.
- Temperature range: Typical reefers hold settings from roughly -25°C (-13°F) for deep-frozen goods up to around +25°C (77°F) for warm-protected cargo.
- Atmosphere control: Controlled-atmosphere and modified-atmosphere reefers adjust oxygen and carbon dioxide levels to extend the shelf life of fruits and vegetables.
What ships in a reefer container?
Common reefer cargo includes fresh and frozen seafood, meat and poultry, dairy, fruits and vegetables, cut flowers and foliage, chocolate and confectionery, and temperature-sensitive pharmaceuticals and vaccines. Each commodity has its own ideal setpoint, and getting it wrong can ruin an entire load.
Reefer drayage: the most time-critical container move
Reefer containers raise the stakes for port logistics. The unit must stay powered, so the window to pick up a container, keep it plugged or running on a genset, and deliver it to cold storage is tight. Every hour a reefer waits is a risk to the cargo and a potential demurrage and detention charge.
Why asset-based reefer handling matters
Reefer drayage works best when the carrier controls its own equipment and can move on short notice. Go Freight is an asset-based Miami 3PL with 100+ company-owned trucks and an in-house chassis pool, and it uses AI gate-time prediction at PortMiami and Port Everglades to schedule pickups around terminal congestion. Pairing fast drayage with the right cold-chain handoff keeps perishable loads at temperature from the terminal onward.
Reefer container vs. refrigerated truck
A reefer container is an intermodal box that travels by ship, rail, and road, keeping the same container sealed across modes. A refrigerated truck (or reefer trailer) is a temperature-controlled trailer used for over-the-road moves and last-mile delivery. Many cold-chain shipments use both: a reefer container for the ocean leg, then a refrigerated truck for regional distribution after transloading.
Frequently asked questions
How is a reefer container powered during trucking?
On the road, a reefer typically runs on a diesel generator set (genset) attached to the chassis or container, since it is no longer plugged into shore or ship power. The genset keeps the unit at temperature in transit.
What is the difference between a reefer and a controlled-atmosphere container?
A standard reefer controls temperature. A controlled-atmosphere reefer also regulates oxygen and carbon dioxide levels to slow ripening, extending shelf life for sensitive produce.
Why is reefer drayage more expensive than dry drayage?
Reefers require gensets, careful monitoring, and faster turn times, and the cargo is more perishable. These factors add equipment and handling costs compared with a standard dry container move.
Get a Miami freight quote today
Go Freight is an asset-based, AI-powered 3PL in Miami handling drayage, warehousing, hazmat, LTL, and last mile. Request a free quote or call (786) 445-0150.