Open Cell vs. Closed Cell Foam

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Memory foam… it’s renowned for its unprecedented ability to mold itself to the unique contours of the sleeper. The trouble is that the material wasn’t initially designed for sleep at all. Rather, it was a creation of NASA intended for use on aircraft to offer cushioning for crash protection. With its visco elastic properties, it would be able to absorb impact in the event of a sudden blow. This is just one reason why memory foam mattresses are popular among sleep partners as they are capable of reducing motion transfer.

Open Cell vs. Closed Cell Foam Comparison Table

Closed CellOpen Cell
Denser and more common
Typically less dense than closed cell foam
Higher closed cell foam r-value makes it good for insulationOpen construction allows better breathability
Resistant to water degradationWeight required for construction less than closed cell with the same r-value
High density prevents mold growthAbsorbs and releases moisture more freely
Environmental benefits over closed cell construction

The Trouble With Memory Foam

When memory foam was introduced in the mattress industry in the 1990’s, one of the most common complaints was that sleepers slept hot. You ideally want your body temperature to drop slightly in order to enter into the deeper sleep stages, so this is especially problematic.

If you’re in the market for a memory foam mattress, the good news is that new technologies have allowed manufacturers to transform what was once an aeronautic tool into a viable mattress material. By understanding the difference between open cell and closed cell foam, you can be on your way to making an educated decision in your next mattress investment.

Open Cell vs Closed Cell Foam

Before we get into the specifics, we first must have some general knowledge of open cell vs closed cell memory foam. By grasping these building blocks, you can apply the information attained to your mattress shopping experience to best ensure you understand exactly what to expect out of the many sleep products you’ll run across.

What is Open Cell Foam?

This foam type is cushiony-soft, and this is because the cell walls are broken, allowing air to fill the spaces in the material. This not only allows your mattress to reduce off gassing but also helps you stay cool through the night.

Since fewer materials are needed to create this less-dense foam type, consumers can often get a good price on a quality material. As you shop, however, it’s a good idea to carefully examine the density of any open cell foam layers in use. This allows you to take a peek at the durability you can expect. In memory foam, you really want to aim for 4-5 pounds per cubic foot. Polyfoams should be no less than 1.8 pcf.

Since open cell foam is less dense by nature, this is an aspect you don’t want to overlook. This is especially true if you’re considering a product that features open cell construction in the comfort (upper) layers of the mattress. Since the majority of direct impact will be absorbed in these levels, density becomes even more important.

What is Closed Cell Foam?

Closed cell foams are great when used in insulation. This is due to their ability to prevent drafts in keeping temperatures regulated. Closed cell foam density is typically high, making it strong and able to effectively resist water damage. Due to its composition, it acts not only to insulate but also to add stability to walls.

While these features are ideal in insulation, they can have quite the opposite effect when used in memory and polyfoams. For starters, you want your mattress to breathe, not resist airflow. Furthermore, when used in the comfort layers, you want a product that’s soft and cushioning, not hard and structural. Closed cell polyurethane foam can often offer an effective and budget-friendly supportive base, but, even at this level, it can cause problems when it comes to the temperature regulation of your mattress.

Is Closed Cell Foam Waterproof?

Closed cell foam features incredible waterproofing qualities that go above and beyond what many realize. When it sets, the barrier created is both air and water tight, and this is also what gives the material its ability to prevent water damage.

2 Part Closed Cell Foam

The waterproofing abilities are created during the mixing process. Since its a two-component material, this means two ingredients are mixed to create closed cell expanding foam. When the combination exits the spray gun, a reaction take place that causes the foam to expand at a rapid rate that allows it to come to a final settlement around 100 times its original size. This expansion aids largely in waterproofing in that small closed spaces are able to be filled effectively.

Understanding R-Value in Cell Foam

Sometimes it’s helpful to analyze concepts from a different perspective. Most people don’t come into direct contact with or even see the foams that lie beneath their mattress covers. Spray insulation is a common use of both open and closed cell foams. This application carries a much different intent than the creation of an open cell foam block.

Open cell spray foam r value represents how well the material prevents heat transfer. While a higher number in the world of insulation means the material will be better able to keep heat from getting in or out, open cell often features a lower r value than closed cell. In the mattress industry, this is a plus as you do want to allow for that added breathability.

Open Cell vs Closed Cell Spray Foam

Whether used in mattress materials or as insulation, let’s take a moment to understand the difference between open cell and closed cell spray foams.

Closed CellOpen Cell
Can be used at very low temperaturesLess expensive with lower density
Adds strength and impact resistanceLower cost and resource use
Higher r-value per inch over open cell Resists moisture
Higher bonding abilities and tensile strengthSuitable for interior use
Suitable for interior and exterior useLow structural reinforcement
High structural reinforcement

While the intended application of open and closed cell spray foams is different, the same general properties are true when it comes to use in sleep products.

Closed Cell: Great for Insulation… Not So Much for Sleep Products

If you’re getting ready to insulate your home, there are a number of ways in which closed cell foam can offer what you’re looking for. However, when it comes to sleep products, open cell structure is the way to go. Traditional memory foam utilized the closed cell construction, and this is where the common complaint of sleeping hot on memory foam largely stemmed from.

The very properties that make closed cell construction great for insulation is what makes it not-so-great in mattress foam. While densities are often lower in open cell foam, there are a number of quality sleep products which have created formulas that allow for reasonable densities to make your mattress last while allowing you to sleep cool. Now that you know this, you’ll be better equipped to make the best purchasing decision.

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