German International School Sydney Uses Shipping Container Classrooms
Simple Steps To Prevent Shipping Container Condensation
Every year millions of tonnes of cargo are stored and transported in shipping containers, and massive amounts of products are damaged or spoiled due to Shipping Container Condensation and moisture build ups that are often referred to as “container rain” or “container sweat”.
Container sweat occurs when the walls of the container are cooled to a temperature lower than the dew point of the air on the inside of the container. Cargo that heats spontaneously (like bananas) can also cause this problem. These changes in the temperature of the container can result in moisture that is inside the container or its contents collecting and condensing, causing damage to the interior of the container as well as goods that are stored within it.
Moisture can be produced by many of the things inside your shipping container: paper, cardboard, wood, mattresses, books – you name it, it’s probably storing a significant amount of moisture.
How Can You Prevent Shipping Container Condensation?
Preventing damage from moisture is far cheaper than fixing damage after it’s happened. Here are some of our suggestions on how you can stop your container becoming a home made shower for what you are storing. Before you do any of these, make sure you’ve removed as much excess moisture as possible. Take a broom and attach an old towel to it before drawing it across the ceiling to absorb any excess moisture or use a sponge mop if you have one handy, dry out your flooring and remove any items that might be damaged already by the damp.
Choose the Right Pallets
By: Mike Mozart
Did you know that your choice of pallets can affect the amount of moisture in your shipping container? Wooden shipping containers can be made from freshly cut wood, or can sit outside all winter, absorbing rain and moisture while exposed to the elements – ending up with a moisture content of anywhere from 35-60%. Heat treating won’t even get rid of all the moisture, it might even make it worse. Consider using plastic pallets that don’t absorb water when storing or shipping goods in your shipping container.
Use Desiccants To Absorb Ambient Moisture
Using desiccants that absorb moisture are one of the best ways to prevent container rain. Desiccants are a substance that create and maintain a state of dryness inside of the container. There are a wide range of options available, with the most common being silica, calcium sulfate, charcoal and calcium chloride. These remove moisture from the ambient air in the container, which in turn lowers the dew point where moisture turns to liquid in the container – meaning less container rain or sweat, if any. Desiccants do a great job of preventing condensation in containers, but you must ensure that you use the correct amount, checking up on it to ensure that it is still doing the correct job and replacing it as necessary.
Desiccants can be applied in a variety of ways, including poles that are installed on the walls of the container, dry bags that are placed on the floor, or special paint that is applied to the roof to prevent rain.
Choose desiccants only when you are using the sort of cargo that suits them, while they might be great for a product that is packed in steel or cardboard, they are terrible for a product that has a moisture content, where absorbing this moisture can result in weight loss and a lower yield of product.
Dehumidifiers & Air Conditioning
By: US CPSC
Dehumidifiers are ideal if a container is being used for long term storage and has ready access to a source of power. They will need to be emptied of water regularly or have a hose plumbed to the outside of the shipping container. Dehumidifiers may also be used to reduce the moisture content in the wooden flooring of a container prior to shipping or long term storage.
Insulation
For some products container insulation may be more appropriate (and considerably cheaper than other alternatives) such as cladding the interior of the container. This shipping container modification keeps the contents warmer than the dew point and prevents extreme differences between the inside and outside of the container, so there is no condensation. Other options could include laying foil encased bubble wrap on the interior of the ceiling and walls, aluminium barriers on the floor or polystyrene insulation.
Ventilation
Ventilation helps prevent condensation by equalising the interior and exterior temperature of the container. Warm moist air is removed by ventilation, while air that is the same ambient temperature as outside is drawn in. Ventilation can be installed in a variety of ways as detailed in our Gateway Guide to Container Ventilation. Of course if it’s wet outside it can cause moist air to come inside the container and perpetuate the problem – probably not the best idea in humid or moist climates.
Do You Need a Shipping Container?
Gateway Container Sales & Hire has a wide range of shipping containers in different shapes and sizes suitable for almost any application, from transportation to storage. All of our containers can be modified to suit your exact needs and specifications. Contact our team of container experts now to find out which container is the best for you.
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