How to Stop Condensation in Shipping Containers with a Desiccant Blanket?

How to Stop Condensation in Shipping Containers with a Desiccant Blanket?

Last Updated on October 15, 2022 by

What is a drying blanket?

The new Absorgel blanket is a desiccant designed to provide effective humidity control in tightly packed drybox shipping containers where there is no space between the cargo and the sidewalls for desiccant products to hang from the panel rings. It is also suitable for trailers and refrigerated units without wall rings for hanging desiccant. The blanket measures 24×59 inches and has an effective absorbent area of ​​24×48 inches. With a large surface area, it ensures fast absorption of large amounts of water on sailings of up to 40 days. Two or three desiccant blankets can do the job of 30 to 60 traditional desiccant bags (120 to 200 grams) in a fully loaded 20-foot container. condition. Desiccant blankets can be used for a variety of dry or wet cargo in bulk or packaged form. The primary absorbent material is calcium chloride with starch and gelling agents to retain moisture in a non-liquid, saline form.

What is container condensation?

Condensation of a container occurs when the walls of the container are below the dew point of air in the container. Since the shipping container is made of metal, the internal temperature may fluctuate significantly due to changes in the weather. When the container cools significantly, the air can no longer retain moisture and reaches the dew point. Once this happens, the moisture turns from the vapor into liquid form, which then accumulates and collects on walls and roofs. This condensation can drip onto your cargo and damage the interior of the container, causing significant damage. Shipping condensation, also known as container rain, can damage cargo by:

  • Packaging deterioration
  • Mold and mildew
  • corrosion
  • warping
  • Powder lumps found in cargo

It is important to know how to stop condensation in shipping containers to avoid these effects and prevent your business from suffering significant loss of profits.

What affects the amount of condensation in a container?

While temperature changes are a contributing factor, learning how to stop condensation in a container means considering all aspects that affect moisture during transport. The amount of condensation in shipping containers may vary depending on temperature, air space, ventilation, moisture content of the cargo being shipped, and container usage.


Temperatures will vary depending on shipping routes and diurnal variations. Liquids can build up in the air when there are significant changes in temperature.

Air Space:

The more space you leave in the container, the more moisture there will be in the air. This makes condensation problems more likely.


If the shipping container is not properly ventilated, airflow will be obstructed. In some transport situations (depending on route and local temperature), insufficient ventilation can lead to further moisture build-up. Airflow helps equalize the temperature inside the container with the temperature of the outside air; the smaller the difference, the less likely condensation will be.

Moisture content of transported carg

Hygroscopic cargo in transport containers has a significant impact on the moisture content. Paper, cardboard, wood, organic materials, refrigerated food and beverages, and other commonly shipped products release moisture when the outside temperature of the container drops. This moisture then collects on walls and ceilings.

How to Stop Condensation in Shipping Containers

While it’s impossible to completely prevent moisture build-up, there are ways to control condensation in shipping containers.

Use the correct pallets

Using pallets to store goods is common practice, but it is important to consider the moisture content of the wood species. It is difficult for the pallet industry to supply pallets quickly, which requires the use of fresh wood – often with too high moisture content. If wood is used while it is still damp, it can cause moisture in the air and exacerbate condensation on shipping containers. Maybe your pallet is not new but made of old wood that was stored in a cold, damp place during the cold winter. These trays may also be full of moisture.

Use desiccant

Desiccant is a product that absorbs excess moisture from the air, effectively lowering the dew point inside the container. Shipping lines often place desiccants inside shipping containers to reduce moisture from the product, packaging, or temperature fluctuations.

Desiccants come in many forms. Depending on your needs and the goods in your shipment, you can choose from the following types of desiccants:

Desiccant Bags:

Desiccant bags are used to absorb moisture from shipping containers and can be hung from ceilings and walls to help reduce airborne moisture. Since the desiccant traps moisture, it lowers the dew point temperature, preventing condensation from forming on the vessel walls.

Desiccant Blanket:

This type of desiccant is laid or suspended on top of the cargo inside the container. It is designed to prevent condensation from forming in the air and protect the cargo below it from water droplets. These blankets feature a breathable membrane that allows existing moisture in the cargo to filter up through the blanket, while offering a leak-proof design that prevents moisture from moving down – also known as container rain. Some desiccant blanket is designed to create a perfectly sealed environment that prevents cold or hot air from flowing through the container, thereby reducing temperature changes that can cause condensation in the container.

Desiccant Pads:

Desiccant pads are essential when transporting refrigerated goods or beverages. These pads are placed under the cargo itself; in the event of a leak, the pads absorb excess moisture to prevent container rain and fungal growth. Many desiccant pads offer thermal protection to keep shipping containers warm to avoid moisture build-up.

If you’re wondering how to stop condensation in a container, desiccants can be an important piece of the puzzle. Desiccant helps prevent condensation build-up, but it’s important to use the right material and the right amount to properly protect your cargo.