Open-Cell vs. Closed-Cell Foam in Mattresses: What's the Difference for Vancouver Sleepers?

Almost every mattress you'll try in a showroom contains open cell foam, but very few shoppers know why. Open-cell and closed-cell foams are built for completely different purposes, and understanding the difference can help you choose a mattress that sleeps cooler, relieves pressure better, and lasts longer.

Closed cell foam is used in yoga mats, pool noodles, and camping pads. The two are genuinely different materials built for completely different purposes, and understanding which one is in your mattress, and why it should be open cell, takes less than ten minutes and makes you a sharper shopper immediately.

Open cell foam has an interconnected cellular structure that allows air to flow freely, facilitating superior heat dissipation and moisture management. Closed-cell foam has completely sealed cells with no connection between them, making it dense, waterproof, rigid, and terrible for sleeping on.

What Is Open Cell Foam?

A foam is classified as open cell when more than half of its cells are open. Open-cell foam behaves more like a spring. When it is compressed, it can quickly return to its original state due to its unrestricted airflow. Open cell is also soft to the touch, breathable, flexible, and can easily conform to objects.

Picture a sponge. The holes you can see running through it are connected to each other. When you squeeze it, air rushes out. When you release it, air rushes back in. That's essentially what's happening in open cell foam at a microscopic level. The cells, the tiny air pockets within the foam structure, are broken open and connected to one another. Air and moisture vapor can move through the material continuously instead of being trapped in isolated pockets.

This structure gives open cell foam its defining properties. It's soft and flexible. It conforms to the shape pressing against it. It allows airflow and dissipates heat. And it responds quickly to movement because there's no trapped air creating resistance inside the material. Open-cell foams are softer, lighter, and commonly used in comfort options such as cushions, sofas, mattresses, car seats, pet beds, and pillows.

What Is Closed-Cell Foam?

Closed-cell foam is characterized by its dense, compact structure, where each cell is entirely sealed off from the surrounding cells. This design significantly reduces the foam's ability to breathe, limiting airflow and flexibility.

Where open cell foam is a sponge, closed cell foam is more like a block of rubber. The cells inside it are completely sealed, each one containing a trapped pocket of gas with no connection to surrounding cells. Air can't move through it. Water can't penetrate it. It doesn't compress easily and when it does, it pushes back firmly.

Closed cell foam types differ in density and texture. It's a stronger and higher density foam than open cell foam. And it's waterproof. Closed-cell foam also blocks the absorption of air, which is why it's a popular choice for insulation. You're probably most familiar with closed-cell foams in yoga mats and pool floats. These applications need exactly the properties that closed-cell foam delivers: rigidity, water resistance, and structural integrity. None of those properties translate well to a sleep surface.

Open-Cell vs. Closed-Cell Foam: What's the Difference?

Is Memory Foam Open Cell or Closed Cell?

Traditional memory foam, the original viscoelastic foam developed in the 1960s, was largely closed-cell in structure. It was dense, slow to respond, and notorious for trapping heat. This is the foam responsible for the reputation memory foam mattresses developed for sleeping hot. The dense structure held your body heat close to the surface all night, and the slow response came from the same structural rigidity.

Today's memory foam is very different. Most modern memory foam is made with an open-cell structure, meaning the tiny air pockets inside the foam are connected instead of being sealed off. This allows air to move through the material more easily, helping heat escape and making the mattress feel cooler than older versions.

That said, "open-cell" doesn't automatically mean a mattress will sleep cool. Density still plays a big role. A high density open cell memory foam has more material packed into it, so airflow is naturally more restricted than it is in a lower density version. In other words, the open-cell design improves breathability, but the foam's density also affects how much air can actually circulate.

Many modern memory foam mattresses also include cooling technologies such as gel, graphite, or copper infusions. These materials are designed to draw heat away from your body and improve temperature regulation. They can help reduce heat buildup, but memory foam generally retains more warmth than natural latex because it contours closely to the body and has less natural airflow.

Is Latex Foam Open Cell or Closed Cell?

Natural latex is naturally open cell. Whether it's Talalay or Dunlop latex, the material contains millions of tiny, connected air pockets that allow air to move freely through the foam. Every time you shift positions or get in and out of bed, air flows in and out of these openings, helping release heat and moisture instead of trapping them.

This is one of the biggest differences between latex and memory foam. Modern memory foam is made with an open-cell structure to improve airflow, but that structure has to be engineered during manufacturing. Latex, on the other hand, doesn't need to be modified. Its open-cell structure is a natural characteristic of the rubber tree sap it's made from.

Talalay latex, which uses flash freezing and CO2 gelling in its manufacturing process, produces an exceptionally uniform, consistent open cell structure throughout the entire material. Every cell is the same size and the same shape because the flash freezing step locks the structure before settling can occur. This uniformity is why Talalay is known for having the most consistent feel from edge to edge and top to bottom.

Dunlop latex is made using a simpler pour-and-bake process. During manufacturing, some of the heavier particles naturally settle toward the bottom before the foam fully cures. As a result, Dunlop is usually denser, firmer, and more supportive than Talalay. Even so, it still has an open-cell structure that allows air to circulate effectively.

No matter which type you choose, both Talalay and Dunlop latex offer excellent breathability. Their naturally open-cell structure is one of the main reasons latex mattresses are known for sleeping cooler than traditional memory foam.

Does Open-Cell Foam Really Sleep Cooler?

Yes, open cell foam generally sleeps cooler than closed cell foam because its connected air pockets allow air to circulate more freely. As heat builds up while you sleep, some of it can escape instead of getting trapped inside the foam.

However, an open cell design is only one part of the story. How cool a mattress actually feels depends on several other factors.

Foam density

Density makes a big difference. A high density open cell foam contains more material packed into the same space, so airflow is naturally more limited than it is in a lower-density foam. That's why two mattresses can both use open-cell foam but sleep very differently.

The mattress cover

The cover is the first layer your body comes into contact with. Breathable materials like cotton, wool, or Tencel help air move in and out of the mattress, while less breathable synthetic fabrics can hold in heat. Even the best open-cell foam can't perform at its best if airflow is blocked at the surface.

Your bedroom temperature

Open-cell foam helps release heat, but it doesn't actively cool the room. If your bedroom is already warm, the mattress can only do so much. Keeping your room cool is still one of the most effective ways to sleep comfortably.

The mattress construction

The overall design of the mattress also matters. For example, open cell foam paired with pocket coils usually sleeps cooler than an all-foam mattress because the space between the coils gives heat and air more room to circulate. Latex mattresses also tend to stay cooler than memory foam because latex is naturally more breathable and doesn't hug the body as closely.

Is Closed-Cell Foam Used in Mattresses?

Not very often. Most modern mattresses use open-cell foam because it's more breathable, flexible, and comfortable for sleeping.

Closed-cell foam is better suited for products where durability, water resistance, and insulation are more important than comfort. That's why you'll commonly find it in camping sleeping pads, flotation devices, protective packaging, and building insulation.

For a mattress, those same qualities can become drawbacks. Because the cells are sealed, air doesn't move through the foam easily. That means it tends to trap more heat and moisture, while its firmer, less flexible structure doesn't contour to your body as well as open cell foam.

There is one exception you might come across. Some mattresses use high density foam around the edges to improve edge support. This perimeter foam is firmer than the comfort layers, helping prevent the edges from collapsing when you sit or sleep near them. However, it's still typically an open-cell polyurethane foam rather than a true closed-cell foam.

Does Foam Cell Structure Matter More Than Foam Density?

Not really. Both are important because they affect different aspects of how a mattress feels and performs.

Think of it this way:

Cell structure affects airflow. Open-cell foam allows air to circulate more freely, while closed-cell foam traps more heat.

Density affects durability, support, and, to some extent, breathability. Higher-density foam usually lasts longer, but it can also reduce airflow because there's more material packed into the same space.

That's why two mattresses made with open-cell foam can still feel very different. A lower-density open-cell foam is often softer, more breathable, and quicker to respond, while a higher-density open-cell foam is usually more durable and supportive but may retain a little more heat.

There's another factor to consider as well: ILD (Indentation Load Deflection). This measures how firm the foam feels when you lie on it. It's separate from density, which means a foam can be high-density for durability but still have a relatively soft feel.

When comparing mattresses, it's best to look at all three together:

•          Cell structure affects breathability.
•          Density affects durability and support.
•          ILD affects firmness and comfort.

No single specification tells you everything about a mattress. Looking at all three gives you a much better idea of how it will feel, how long it will last, and whether it's a good fit for your sleeping style.

How to Tell If a Mattress Uses High Quality Open Cell Foam

Ask for the foam density. Quality memory foam for a comfort layer sits between 3.0 and 5.0 lbs per cubic foot.

Check certifications. CertiPUR-US confirms the foam is free of harmful chemicals and meets VOC emission limits. It's the baseline you should expect.

Look at the full construction, not just the comfort layer. A quality open-cell foam over a pocket coil system with natural fiber covers tells a better story than open-cell foam sandwiched in an all-foam stack.

Ask what the manufacturer says. A brand that knows their product can tell you the foam type, the density, and the certifications. If those answers aren't available, that's information in itself.

Check the warranty. Longer warranties on foam layers reflect manufacturer confidence in the material's durability. A 10-year warranty on the foam is meaningfully different from a general mattress warranty that doesn't specifically address the foam layers.

What We Recommend for Vancouver Mattress Shoppers

Don't chase the open cell label by itself. It's the right starting point, not the destination. The full construction of a mattress, what the open cell foam is paired with, what covers it, and what's underneath it, determines how much the open cell structure actually benefits your sleep.

Compare densities alongside cell structure. Look at the full material stack from cover to base. And test mattresses in person in your actual sleep position for long enough to feel how they manage your body heat rather than just how they feel in the first thirty seconds.

At King of Mattresses, one of the best mattress stores in Vancouver, we carry mattresses across multiple foam and latex constructions and our team can answer specific questions about density, certifications, and thermal performance. Come in, ask the hard questions, and feel the difference between materials in person.

Visit us at 2162 Kingsway, Vancouver. The material in your mattress affects how you sleep every night. It's worth understanding properly before you buy.