What Is A Reefer Trailer? (trucking industry)

What is a reefer trailer? A reefer trailer, in the trucking industry means a trailer that is refrigerated, and that refrigerated trailer is attached to an 18-wheeler or semi, so it can transport perishable items that require a specific temperature during transport. The reefer trailer also has added insulation.

The reefer trailers are used to keep goods at a preset temperature so that the perishable freight doesn’t spoil.

Sometimes that temperature is above the outside air temperature but is usually lower.

Reefer trailers can transport numerous items such as fruits, vegetables, pharmaceuticals, seafood, and many more items.

What Does a Reefer Trailer Look Like?

A reefer trailer looks similar to a regular box trailer, but the reefer trailer has added insulation along with a refrigeration unit on the front of the trailer.

See the picture below, I circled what the refrigeration unit looks like from the outside:

The refrigeration unit has the engine, a compressor, an evaporator, along with the condenser. It’s really not much different than a refrigerator in your home except bigger. 

The refrigeration unit also has a controller display (pictured below) and keypad along with a heater panel.

This picture shows you what a controller display and keypad look like:

The refrigeration unit will need to be pre-set before the product is picked up so that it is the required temperature for the freight.

The reefer will maintain the preset temperature while the freight is transported. 

The diesel engine will provide the power that the refrigeration unit needs.

Along with the refrigeration unit on the front of the trailer, the reefer trailer also has a few other features that a regular box trailer doesn’t have, which include a translucent roof layers that is also tear resistant, a sidewall liner that is impact absorbent, and a scuff plate.

On the roof of the reefer trailer it has the ability to reflect the heat and UV waves as well, helping maintain a constant temperature.

How Does a Reefer Trailer Work?

There are three major components that work together for the reefer trailer to operate, which include:


The compressor operates by absorbing and compressing the gaseous refrigerants.

The compressor takes the gas, then pressurizes it by turning it into a liquid refrigerant that dispenses the heat from the compressor body along with the neighboring air.


The condenser obtains the warm refrigerant liquid, then relocates it into the exchanger. The refrigerant liquid then travels to the tubing walls along with the fins.

The area on the fins is very large, and it is assisting to cool the air outside. When it has reached this stage, the warm refrigerant liquid has nearly lost most of the heat that is in the condenser.


From the condenser the cool refrigerant is flowing inside of a metering valve, then it travels into the evaporator, and this is when it (refrigerant) starts to quickly expand.

When it has reached this stage, the refrigerant has transformed into gaseous form, then it begins to circulate into the reefer trailer so the freight inside is at the temperature that it is desired.

How Are Refrigerated Trailers Powered?

A typical refrigerated unit is powered by its own small diesel engine. This means that the refrigerator unit on the trailer can continue working even though the tractor trailer is not running.

This is how drivers maintain a specific temperature in the reefer trailer even while they sleep. The driver has an added responsibility to make sure the refrigeration unit also has enough diesel.

There are sensors with each refrigeration unit that monitor the temperature for the freight, the engine coolant temperature, and the pressure for the compressor discharge.

A refrigerated trailer has a large temperature range, which include from -65 to 40 degrees, and from -85 to 104 degrees.

What is The Difference Between a Reefer and a Dry Van?

A reefer trailer and a dry van trailer are very similar with one another except the reefer van is insulated and has a temperature control unit.

A dry van trailer can be used for hauling any kind of freight that doesn’t require a preset temperature.

To see my explanation of the dry van trailer and some pictures on them then check out this article I recently wrote.

A dry van trailer is able to protect the freight theft, damages, and weather elements but does not have any way of managing temperature.

They are best used for longer hauls.

A reefer trailer can haul perishable goods that require cooling or heating preset temperatures.

A reefer trailer has the added expense for fuel, because the refrigeration units has to be powered on at all times.

Do Reefer Trailers Heat?

Like I said earlier the reefer trailer maintains a specific temperature that is needed depending on what the freight requires.

A refrigerated trailer has a large temperature range, which include from -65 to 40 degrees, and from -85 to 104 degrees.

The reefer will at times be needed to hold a desired temperature higher than the outside temperature.

For example, if you are transporting potatoes during a cold winter you may have to set the temperature at 50 degrees.

Driving a Reefer Trailer Pros

There are some pros and cons to driving a reefer trailer versus a regular dry van trailer. Here are some of them:

Driving a Reefer Pros: 

  1. A driver with a reefer trailer usually makes more money
  2. Reefer truck drivers are in demand, even if the economy is not booming
  3. Many grocery store chains have their own loading dock, so it is easier for the driver to maneuver
  4. Usually a lumper (someone that unloads the trailer) or employee will unload the trailer for the driver

Driving a Reefer Cons:

  1. Reefer trailers need to be cleaned out after each load
  2. The reefer unit constantly runs, so you will need to fuel more often
  3. The refrigeration unit runs nonstop, even during the night, and can be hard to sleep for some drivers
  4. Reefer drivers usually drive at night, because reefer loads are usually morning deliveries

Reefer Trailer Summary

A reefer trailer is very similar to a dry van or box trailer, except it has a refrigeration unit attached to the front of the trailer, added insulation, sidewall liner that absorbs, translucent laying on the roof that is also tear-free, and a UV waves that reflects heat.

A reefer trailer is usually used to haul products that need preset temperatures, and some of the products are fruits, vegetables, plants, seafood, pharmaceuticals, and many more items.

A truck driver that has a reefer trailer usually makes more money due to the type of freight being hauled.