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How to Choose the Right Insulation for Your Modified Shipping Container

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Choosing the right insulation for your modified shipping container can be daunting, considering how many different types of insulation are available. Getting the right container insulation ensures that your container is a comfortable environment for you to spend time in.

Poor insulation allows heat or cold into your container, mimicking the weather in your area. Not only does proper insulation help control the temperature of your modified shipping container, but it helps keeping energy costs low.

Which insulation should you choose for your cargo container? In this article, we’ll look at different types of insulation, as well as the most common type used for shipping container modifications.

Shipping Container Insulation Types

In total, there are about 17 different subtypes of insulation, which fall under four specific categories. All insulation is rated in what is known as the ‘R-value’. The R-value is the level of resistance to the heat that the insulation is blocking.

The higher the R-value, the better the prevention of heat energy transmission. In other words, the better the insulation, the better the temperature inside your shipping container. The most common container insulation types are:

  • Blanket insulation
  • Loose-fill insulation
  • Expanded foam insulation
  • Spray foam insulation

Blanket Insulation for Storage Containers

Blanket insulation is ideal for shipping container offices and living spaces, making it a popular choice.  Fluffy and compressible, blanket insulation makes use of long fibers that is also a low-cost option and easy to install.

Varieties of this type of insulation include:

  • Fiberglass — the most common type of wall insulation. It’s made from superheated sand, or recycled spun glass, that’s turned into thin fibers.
  • Slag, Mineral and Rock Wool– this is made from spun minerals, ceramics or slag.
  • Sheep’s Wool – as it sounds, it’s made by shearing wool from sheep.
  • Cotton – it’s usually made from recycled denim or blue jeans, resulting in a blue tinted color. Cotton is typically more expensive than other types.

Loose-Fill Insulation for Storage Containers

Loose-fill insulation is good for existing areas that have been finished, oddly shaped areas and around barriers.

This type of insulation is common in attic areas, where insulation needs to be added or replaced, but it can work in modified cargo containers as well. It’s installed either through blower or pouring. There are three subtypes of loose-fill insulation:

  • Cellulose– it’s made from recycled paper or paper products that have been shredded and then blown in by machine.
  • Fiberglass – it’s similar to the blanket fiberglass, but loose-fill fiberglass is less dense and not as tightly bound.
  • Vermiculite/Perlite – usually added to wall cavities. This type is made from minerals that have been heated and expanded like popcorn.

Expanded Foam Insulation for Shipping Containers

Expanded foam insulation is popular choice for shipping containers and in most cases, usually has the highest R-value of insulation.

Expanded foam is created offsite and placed into boards and panels that are sized for differing wall heights. It is also self-supporting. This insulation can be attached to studs or glued into a container wall.

Types of expanded foam include:

  • Open Cell Polyurethane (oc PU)– this is thin and filled with air, giving the insulation a spongy texture, with a lower R-value.
  • Closed Cell Polyurethane (cc PU) – it uses a blowing agent that fills tiny, microscopic cells with a heat conduction gas, increasing the R-value.
  • Extruded Polystyrene (EPS) – composed of small, fused plastic beads, this is the foam you’re used to seeing in the form of coffee cups. Insulation kits are usually made from it.
  • Expanded Polystyrene (XPS) – it starts as a molten material that is then pressed into sheets.
  • Polyisocyanurate (Polyiso) – similar to polyurethane but more rigid.

Spray Foam Insulation for Shipping Containers

Spray foam insulation is also a popular choice when it comes to container insulation. Spray foam is best used for equipment enclosures that are temperature sensitive. Containers that are being used for mobile switch rooms, UPS, generator systems and labs usually have this type of insulation.

Types of spray foam insulation include:

  • Open Cell Spray Polyurethane (oc SPF)– it’s a less desirable type of spray foam insulation because it has a lower R-vale.
  • Closed Cell Spray Polyurethane (cc SPF) — as the most common shipping container insulation, it has an extremely high R-value and is good at controlling moisture.
  • Damp Spray Cellulose — this is also made from recycled paper products.
  • Cementitious Foam –it’s an extremely light mixture of natural minerals, water and air that’s like concrete. It’s eco-friendly, non-toxic, and non-flammable.

Open Cell and Closed Cell spray polyurethane are expanding spray foam while the bottom two are non-expanding. Expanding spray foam means that it expands to fill the area, while non-expanding means it shifts around to fill up the area.

Different types of insulation can be combined, depending on what you’re using your modified storage containers for. For example, you could use expanded foam for a container office and spray foam for a generator or switch room.

Southwest Mobile Storage offers spray foam insulation for our containers and mobile offices, providing both temperature and moisture control and helping to reduce noises from the outside. Now that you know how to choose the right insulation, discover if you also need to add ventilation to your shipping container as well.

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