Unless you’re a trucker, all the terminology can be a bit confusing. Take, for example, the reefer trailer. In this article, we’ll explain exactly what it means, what a reefer trailer is used for, and more specifications.

What is a reefer trailer: A reefer trailer is a semi-trailer that has a refrigerator unit on it. The purpose of a reefer trailer is to move perishable goods such as vegetables, meat, and dairy. It can also transport flowers and pharmaceuticals. A reefer trailer is meant to maintain one specific temperature, according to what it is transporting, and is not meant to increase or decrease the temperature as the goods are being moved across the country.

While reefer trailers have the same outside dimensions as standard semi-trailers, the refrigerator units take up more space. Furthermore, the walls are thicker due to the heavy insulation needed to control the temperature.

What is a reefer trailer?

To put it simply, a reefer trailer is a trailer that has climate control. This is usually a refrigerated space but can sometimes be a heated space.

A reefer trailer is also known as a refrigerated trailer. The term “reefer” is a more common term used among truck drivers as a short form of “refrigerated trailer”.

In order to keep the cold temperature, the reefer trailer must be airtight. The temperature inside is controlled via a refrigeration unit and the walls are insulated to keep the cool temperature steady.

What does a reefer trailer do?

A reefer trailer’s purpose is to ship perishable goods from one area to another. These goods must be kept in a certain area and are considered perishable foods.

If you will at some point put your goods into your home refrigerator, then those goods will have been shipped by a reefer trailer.

Common goods that a reefer trailer transports include fruits and vegetables, along with meat. Other goods that require the use of a reefer trailer but are often forgotten about include flowers and pharmaceutical products.

Perishable foods, especially fruit, vegetables, dairy, and meat products, have a limited shelf life. The race is on as soon as these foods are packaged to get to the store and then to your home in as short a time as possible.

Without a reefer trailer, these goods won’t last the entire journey. This is especially true when you need to transport perishable goods across the country or even across the planet.

The whole purpose of a reefer trailer is to maintain a consistent temperature. Once a certain product is inside the trailer, a temperature is agreed upon.

The reefer trailer is not meant to increase or decrease that temperature. If this happens, goods can spoil.

Parts of a Reefer Truck or Trailer

Parts of a Reefer Truck

The compressor

In order for a reefer trailer to stay cool, it needs a compressor. This is somewhat similar to a home’s refrigerator, except a lot larger and more powerful.

The compressor has a small engine that is used to work with the refrigerant gas. This substance starts as a gas but then once it goes through the compressor, it turns into a liquid.

The result of this process is that a lot of heat is generated, which is the opposite goal of having a refrigerated truck. The other parts of a reefer truck will take care of this excess heat.

The condenser

After the refrigerant gas turns into a liquid, it is then moved into the condenser. The goal here is to cool the process down.

You can think of the condenser as similar to a home’s radiator. There is a series of fins and tubes that work the liquid through so that it can be used in the reefer trailer.

The evaporator

Now that the liquid is cooled, it can be used properly in the reefer trailer. The liquid passes through a metering valve inside the evaporator.

The settings on the evaporator are important to maintain or else you won’t have the right temperature. Furthermore, a consistent temperature is paramount, or else your food will quickly spoil.

As the liquid passes through the evaporator, it becomes a gas again. Some heat is absorbed from the finned coils of the evaporator but not enough to heat the gas where it can’t be used.

Finally, the process is repeated as the cool air inside the reefer trailer makes its way back to the compressor so that there is a steady and measured flow of cool air.

Reefer Containers vs. Reefer Trailers: What’s the difference?                

You may hear the terms reefer container and reefer trailer used interchangeably. This is because a trailer is a type of container that is then hooked up to a truck for transportation.

A reefer container is simply a unit that is not hooked up to a truck yet. Reefer containers are essential for transporting perishable goods across the ocean.

Just think about exotic food such as bananas and pineapples. These are grown in South America and then shipped via boat to North American ports.

Then, a reefer container is attached to container chassis and thus becomes a reefer trailer.

There is a difference, however, with larger shipping containers that need to be mounted on trailer frames.

Reefer trailers are already set up and have their wheels attached to the entire container.

Dry Van vs Reefer

Another term to be aware of is a dry van. This is much different than a reefer trailer because there is no option to cool the inside temperature.

With a dry van, you can ship products such as clothing and furniture. It provides a safe, dry environment, hence the name.

The biggest takeaway is that anytime you need to transport perishable, temperature-sensitive goods, you need to use a reefer trailer.

What type of fuel does a reefer trailer use?

Reefer fuel is diesel, but a different grade than is used for semi trucks.

Reefer Fuel vs Tractor Fuel

For fuel for the truck, standard diesel is usually used. You can also use tractor fuel, which is also known as standard number 2 diesel.

To power the refrigerator unit on your reefer trailer, you need reefer fuel. This is not meant for vehicles that drive on the road.

To help make sure you don’t use reefer fuel by accident to power your truck’s engine, the fuel is dyed red.

While farm and other agricultural equipment can use reefer fuel, large semi-trucks can’t. It is not meant for any road use and not only will your equipment suffer, but you can face heavy penalties.

Reefer fuel is cheaper than diesel, which is why it is used for the refrigeration unit on a reefer trailer.

Furthermore, reefer fuel will run a reefer trailer’s refrigeration unit for about three to five days, depending on the outside temperature and how often the trailer is accessed.

How Long Is a Reefer Trailer?

From the outside, a reefer trailer looks almost identical to a regular semi-trailer. They come in 48′ and 53′ (most common), which is standard for other trailers.

The main difference is that the refrigerator unit will be visible on the outside front of the trailer. This is necessary to help circulate the air properly inside the trailer, and as it is mounted on the outside, it won’t take up precious space on the inside of the trailer.

How Wide Is a Reefer Trailer?

Similar to other semi-trailers, a reefer trailer measures 8.5 feet in width. This standard size is important as it allows any truck to attach to it.

The standardization is also important so that trucks can safely tow it on highways. If a reefer trailer is too wide, it can easily cause accidents to happen.

Check out this article to see how many pallets can typically fit in a reefer trailer.

What Is a Reefer Trailer’s Height?

The standard height for a reefer trailer is 13.5 feet tall. However, the internal height is considerably less, measuring about 8.5 feet from floor to ceiling.

The height of a reefer trailer can vary so any time you are hauling one, you will need to know the exact measurements. While most major highways can accommodate taller reefer trailers, some will post alternative routes if there are older, shorter overpasses.

How Much Does a Reefer Trailer Weigh?

When empty, a reefer trailer can weigh about 15,000 pounds. This is more than a basic trailer as a reefer trailer will have the refrigerator unit as well as thicker, insulated walls.

What is inside will then affect the overall weight of a reefer trailer. This is entirely dependent on what types of goods are stored inside the trailer.

However, every trailer, including a reefer trailer, has a maximum freight weight. This is around 44,000 pounds at time of writing.

Whenever you are transporting goods, they will be weighed properly. After everything is loaded, the reefer trailer will be weighed to ensure it meets transport standards and that the truck can actually pull it safely.


A reefer trailer is simply a shortened name for a trailer with a refrigerated unit. Reefer trailers are used to ship perishable goods such as meat, dairy, and vegetables. To run a reefer trailer, use regular diesel but to run the refrigerator unit, use reefer fuel.