What Is a Reefer Trailer?
Visually, from the exterior, a reefer looks exactly like a semi-trailer.
Actually, a reefer is a semi-trailer with added functionality.
Below, find out more information about reefer trailers.

What does reefer mean in trucking?
In trucking, a reefer trailer is a semi-trailer that has the ability to maintain a cool environment inside during transportation of the product.
See also the difference between reefer trailer and dry van.
Reefers maintain a cool environment around the product
First of all, under the term refrigerated freight fall all the products that require specific temperature ranges during their transportation to avoid their alteration.
Products requiring temperature control during transit are fruits, meat, fish, seafood, vegetables, dairy, and also non-food products such as flowers, pharmaceuticals, etc.
These temperature ranges are set by the customer, which means that the driver has to follow this instruction.
To do that, the driver uses a thermostat that is located outside the trailer to set the reefer continuous or cycle settings.
What does the cooling process look like?
Below, find a short breakdown of how does a reefer trailer work process.
It's important to understand that the reefer's refrigeration system only maintains a set level of temperature but it doesn't increase or decrease the temperature level inside it.
Because of that, the cargo has to be brought to the desired temperature level before being loaded in the reefer.
Reefers maintain the temperature and humidity inside the trailer during the whole transit time. This entire refrigeration cycle is done by manipulating the inside air.
To create the ideal environmental conditions for the transported products, reefers have multiple sections such as:
- The control unit section:
The control unit allows you to set and adjust the internal environment inside the reefer such as the temperature, the alarm conditions, and in some cases ventilation and humidity levels.
- The interior fans section:
Interior fans located inside the reefer help to circulate the air inside the reefer to promote adequate temperature control and stability.
With the help of an reefer trailer air chute attached to the trailer's ceiling, the airflow is blown to the back of the trailer and, from there, it circulates under the palletized freight. In this way, the flow of cold air inside the trailer is taken care of.
- The fresh air vent section:
The fresh air vent allows the air from the outside of the trailer to enter and remove any gasses from the container, such as fruit-ripening ethylene gas.
- The evaporator section:
Excess moisture in a reefer can damage products, quicken food spoilage, and break down packaging, leaving contents vulnerable.
The unit evaporator helps to maintain the moisture inside the container. The reefer unit evaporator can either heat or cool the air that circulates past it from the fan.
- The condenser section:
Condensers may have air or water cooling.
The reefer is powered by a separate reefer fuel source.
Drivers need to ensure there’s enough fuel in the tank, especially on long journeys.
Typically, a full tank will last a few days, depending on the difference between the temperature of the load and the outside temperature.
Also, to avoid any breakdowns of the reefer trailer unit it is recommended to do regular reefer trailer maintenance.

Options to acquire reefer trailers
There not many types of reefer trailers out there.
Besides that, there are a few refrigerated trailer manufacturers that you might want to check.

Consider an electric reefer trailer
An electric reefer trailer is an alternative to traditional reefers that run on fuel.
Due to that, electric reefer trailers are considered to be more fuel efficient and more environmental friendly.

Are refrigerated trailers airtight?
Refrigerated trailers are built with insulated walls made of steel, plastic, or some other non-porous material, and sealed very well to prevent heat from entering them, and keep the cool air inside where it belongs.
What are the dimensions of a reefer trailer?
A reefer's inside total cargo space is lesser than the exterior due to the refrigeration equipment taking up some of the room inside the container.
53 feet reefer trailer dimensions and capacity | |
---|---|
Overall length | 53 feet |
Inside length | 51'6" |
Overall height | 13'6" |
Inside height | 103.5" |
Overall width | 102" |
Inside width | 97" |

How to load a reefer trailer
Loading freight into a reefer is different than loading freight into a dry van.
The refrigerated freight should be brought to the required temperature range prior to loading it into the reefer. By the time, it has to be loaded into the trailer it should have the required temperature range so that the truck driver can set the exact same temperature range to be maintained inside the trailer during the transportation.
If this procedure is not followed then, by the time the truck arrives to the delivery, the products may be altered, which translates in loss of revenue to the customer.
See the steps to load a reefer trailer.