Insulated Shipping Container: Size, Dimensions, and other Specifications Explained

insulated shipping container for sale

Are you considering purchasing or leasing an insulated shipping container? But confused about how to choose the best one? Well, this blog here, gives you an in-depth analysis of what insulated shipping containers are! Why do we need them? What are their functions and types as well as their pros and cons? It will provide you with the required insight, helping you make an informed decision before you make the purchase.

All goods aren’t resistant to external conditions on long voyages. Perishable products such as foods, photosensitive and heat-sensitive chemicals require specialized units to prevent them from rotting or getting spoilt. Insulated freight units offer the preferable conditions and protection to ship these goods without breaking the cold chain.

Let’s have a look at the different types of maritime cargo containers that fulfill the need of shippers worldwide in general:

1. Dry Van
2. Pallet Wide
3. Double Door
4. Side Door
5. Open Top
6. Hard Roof Open Top
7. Flat Rack
8. Platform
9. Insulated
10. Reefer
11. Bulkers
12. Tanks

What are insulated shipping containers?

It’s frequently the case that standard cargo units cannot meet the needs of the cold chain during the transportation procedure. Different products need different environments for optimal preservation. Heat and light-sensitive goods like food, medicines, or industrial chemicals need stable conditions to ensure their required quality. Hence, they cannot be stored in normal steel shipping containers as the freight boxes need to adapt to surrounding temperatures and humidity.

Therefore to overcome such issues, an insulated cargo container, also called a non-operational refrigerated unit is used.

The slim steel wall of a standard dry van container can’t ensure a constant internal temperature when exposed to the external climate. On the contrary, insulated cargo units intercept damages due to temperature fluctuations during hauling. They also help to avoid shipping container condensation that results due to rainwater or moisture finding its way inside the maritime container.

Why do we need insulated shipping containers?

Let’s look at the main products that use this facility to comprehend why so many logistical resources find themselves spent on insulating and controlling temperature for certain goods. To maintain pharmaceutical products, fresh produce, beverages, frozen goods, and chemicals often require a certain temperature. In addition to that, they also need protection from contamination by ensuring the filtration of air entering and leaving the metal shipping containers. Insulation completely seals a cargo container off from the outside and thereby maintains a stable condition for the transported goods.

A cold chain refers to a supply chain system that keeps certain goods in a permanent cold state throughout their journey from the supplier to the customer. By maintaining a stable cold state, we can prevent the spoilage of goods among several other issues. It also ensures long-term storage for the products.

How to insulate shipping containers?

Heat-proofing a standard freight unit isn’t a simple task. The most economical and hassle-free way to ship perishable goods is to directly buy an insulated shipping container.

However, if you want to do it yourself, here are some ways:

Two-layer walls

Here, two-layer walls cover the container wall. This leads to the creation of a vacuum between the layers thereby preventing the transfer of heat from the exterior to the interior and vice-versa. This method of ensuring the temperature is very useful as it requires the least expenditure. The only requirement to lower the temperature initially happens to be coolants. Therefore, the vacuum structure traps in internal energy and prohibits it from heating up due to the surroundings.

Additional internal layer

An additional layer finds itself attached on top of a wooden frame. The layer is then fully secured to ensure that the interior stays condensation-free.

Lined up container walls

The container walls find themselves lined up with liners usually built into the walls that easily absorb and dissipate heat. These include liners and thermal blankets and find themselves composed of multiple layers.

Thermal sheets are large sheets that are usually wrapped around individual pallets, and not around the shipping container. On the other hand, liners define structures built into the walls of the boxes to conserve heat.

Gas-filled chambers

A gas-filled chamber around the whole insulated container can seal in the heat and maintain a steady temperature inside. Consult a professional agency to add such a structure to a standard container. It’s especially true if you want to use it to ship sensitive goods. Using thermal blankets around individual pallets can be done manually to insulate on a smaller scale. Smaller boxes with gas-filled chambers can also be placed inside the shipping unit. Bubble wrap is an effective solution for lower insulation or temperature control.

Types of insulated shipping containers

The type of insulated maritime container depends on the type of goods that the container transports.

Regular Ice Totes

This container type finds application in food processors, seafood processors, and wineries to ship their goods. This type of insulated cargo unit provides optimum temperature control due to foam-filled double-wall.

Dry Ice Totes

This type of insulated freight container finds its composition made of compounded-melt blend low-density polyethylene plastic. It finds itself best suited for the transportation of frozen goods like dry ice and ice cream for a short voyage. This type of container has a significant resistance to impact.


This unit category is perfect for onboard handling, thawing, or freezing. It establishes applications onboard vessels, for instance, to sort, grade, store seafood, and reduce the thaw time by half.


This container type finds its use to transport fresh goods to markets, supermarkets, or vendor shows. They are portable, keeping food and beverages cold without using a mechanical refrigeration system.

Insulated shipping features and container sizes

They come in different sizes of 20ft, 40ft, and 40ft high cube insulated containers for better transportation and storage solutions. So, the approximate date of the dimensions is given below.

20ft Insulated Shipping Container

Internal dimension 19’1”x7’6”x7’5”
External dimension 19’10” x 8’ x 8’6”
Door Opening 7’6” x 7’5”
Max gross weight 67200 pounds

40ft Insulated Shipping Container

Internal dimension 39’2” x 7’6” x 7’5”
External dimension 40’ x 8’ x 8’6”
Door Opening 7’6” x 7’5”
Max gross weight 67200 pounds

40ft High Cube Insulated Shipping Container

Internal dimension 39’2”x7’4”x8’4”
External dimension 40’ x 8’ x 9’6”
Door Opening 7’6” x 8’4”
Max gross weight 74960 pounds

Cooling and other features in insulated shipping containers

There are several options to create the right temperature in the heat proof box depending on the type of products it contains.

The easiest choice is to use chunks of ice or contrived slurry ice to reduce the preliminary temperature. Slurry ice defines microcrystals suspended in water with a decreasing freezing point and an efficiency of 70%. It doesn’t leave any residue but is toxic in large quantities. Hence, its use is only valid under certain conditions.

Chemical Phase Changing Materials (PCMs) find their implementation to set the preliminary temperature in the unit. It absorbs heat and lowers the temperature. It is usually solid but can be liquid as well. It’s a gel within a specific temperature range. To prevent the spoilage of goods, air filters find themselves attached to the container to improve air circulation. Nitrogen is injected into the unit for the same reason. A temperature detector must check for temperature fluctuations.

Problems and challenges

Maintaining the cold chain is the biggest issue when it comes to transporting perishable products.

The elements incorporated for insulation and shielding, like waste matter, derivatives, packing medium, and coolants aren’t recyclable. They end up in landfills and incineration sites where the toxic chemicals are causing harm to the environment. However, to combat this situation and ensure proper disposal, trials are underway.

The difference between reefers and insulated containers

Simply put reefer consists of a motor and therefore requires an energy source like a generator on the vessel. On the contrary, a non-refrigerated unit depends on similar properties as a reefer. A large heatproof unit that sustains a steady temperature that doesn’t have an active freezing system. Keep in mind the type of goods undergoing transportation when opting between an insulated and refrigerated container. To preserve specific food items like seafood that require freezing temperatures for transportation over long distances a reefer would be ideal. Whereas, for transporting vegetables like onion or potato that aren’t very temperature sensitive can find transport within an insulated box.

In conclusion, we can say that the transportation of some goods like medicine, chemicals, and food items greatly depend on insulated shipping containers. You can find all types of maritime cargo units irrespective of their type at LOTUS Containers. Whether you are looking for a new shipping container in Ohio, we provide shipping container grades of all kinds.

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