Serene® is a polyurethane comfort foam developed by Carpenter Co. It contours to your body like memory foam, but it isn't memory foam. It's built with billions of microscopic air capsules that give it that slow, sinking feel while adding support. Unlike memory foam, it doesn't stiffen in a cold room, it releases heat faster and it springs back about four times quicker when you move.
We use a 2" layer of Serene as the comfort layer in both the Cozey Foam Mattress and the Cozey Hybrid. The most common question we get about either one is "so, is it memory foam?" The honest answer is that it was designed to give you what people like about memory foam, without the parts they don't.
This guide explains what Serene actually is, how it compares to memory foam and standard foam in lab testing, why it behaves better in a Canadian winter, and where it falls short.
On This Page
- What Is Serene Foam and Who Makes It?
- Serene vs. Memory Foam vs. Standard Foam at a Glance
- Does Serene Relieve Pressure Better Than Memory Foam?
- Does Serene Foam Sleep Hot or Get Hard in the Cold?
- Is Serene Foam Bouncy or Slow?
- How Durable Is Serene Foam?
- Is Serene Foam Safe?
- What Are the Downsides of Serene Foam?
- Who Is Serene Foam Right For?
- How Cozey Uses Serene Foam
- Sources
What Is Serene Foam and Who Makes It?
Summary: Serene® is a comfort foam developed by Carpenter Co., the world's largest vertically integrated maker of polyurethane foam. Its "memory" feel comes from trapped air, not from heat sensitive chemistry.
Carpenter was founded in Richmond, Virginia in 1950 and develops its foams at the M.H. Reinhart Technical Center, its research lab in Richmond. Serene came out of that lab, and Carpenter markets it as a comfort or transition layer for mattresses, toppers and pillows.
How it works
Most foams fall into two families:
- Memory foam (viscoelastic foam) uses chemistry that softens with body heat. That's what gives it its slow, molding feel.
- Standard polyurethane foam springs back quickly and feels more like a traditional cushion.
Serene is made with standard polyurethane chemistry, but its cell structure is different. Carpenter calls it Supportive Air Technology™: the foam is filled with billions of microscopic air capsules. When you press into it, the air resists being pushed out, so it takes more force to compress. That's the extra support. When you get up, the air flows back in gradually, which is where the slow, contouring "memory" feel comes from.
A simple way to picture it: memory foam molds to you because it warms up and softens. Serene molds to you because it's cushioning you on air.
Serene by the numbers
Serene by the numbers
| Property | Serene® (softer grade) |
|---|---|
| Chemistry | Conventional polyurethane, not viscoelastic |
| Density | 2.5 lb/ft³ |
| Firmness (25% IFD) | 12 lb minimum (a firmer 22 lb grade also exists) |
| Resilience (ball rebound) | 20% to 30% |
| Certification | CertiPUR-US® |
Source: Carpenter Co. Serene® foam specification sheet.
Serene vs. Memory Foam vs. Standard Foam at a Glance
Summary: In Carpenter's testing, Serene gave more support and lower pressure than memory foam, didn't change with temperature, and recovered about four times faster. Memory foam still absorbs motion best.
Serene vs. Memory Foam vs. Standard Foam at a Glance
| Serene® foam | Memory foam | Standard polyurethane foam | |
|---|---|---|---|
| Feel | Contours slowly, then supports | Deep, slow sink | Quick, springy push back |
| Support (force at 40% compression, lbf) | 11.76 | 9.63 | 10.61 |
| Peak pressure, lying on your back (mmHg) | 58.7 | 220 | 72.5 to 98.3 |
| Rebound (ball rebound test) | About 20% | About 5% | About 45% |
| Temperature sensitivity | None detectable in normal use | Firms up as the room gets colder | None detectable in normal use |
| Motion isolation | Good | Excellent | Low |
| Sleeps hot? | Releases heat faster than memory foam | Known to hold heat | Depends on the foam |
All figures come from Carpenter Co.'s lab testing on foam samples about 2" thick, comparing Serene to memory foam and standard foams of similar firmness. They describe the foam on its own, not a finished mattress, but they show why it behaves the way it does.
Does Serene Relieve Pressure Better Than Memory Foam?
Summary: In Carpenter's pressure mapping, Serene had the lowest average and peak pressure of the four foams tested, on the back and on the side. Peak pressure on the back was 73% lower than memory foam.
Pressure mapping uses a sensor mat between a person and the foam to show where weight concentrates. Two numbers matter most. Average pressure tells you how evenly your weight is spread. Peak pressure shows the hot spots, the places that make your arm go numb or have you shifting around at 3 a.m. Lower is better for both. A larger contact area means the foam is holding more of your body instead of just your heaviest points.
Carpenter tested 2" samples of four foams with similar firmness: Serene, memory foam, and two standard polyurethane foams.
Lying on your back
Tested on a very firm surface underneath.
Lying on your back
| Foam | Average pressure (mmHg) | Peak pressure (mmHg) | Contact area (sq. in.) |
|---|---|---|---|
| Serene® | 18.61 | 58.71 | 411.0 |
| Standard foam A | 20.02 | 98.31 | 376.8 |
| Standard foam B | 20.33 | 72.52 | 366.8 |
| Memory foam | 21.41 | 220.00 | 351.3 |
This is the most striking result. Memory foam showed a concentrated pressure point of 220 mmHg, in the hip area. Serene peaked at 58.7 mmHg while supporting 17% more of the body's surface.
Lying on your side
Tested on a medium support surface underneath.
Lying on your side
| Foam | Average pressure (mmHg) | Peak pressure (mmHg) | Average shoulder pressure (mmHg) | Peak shoulder pressure (mmHg) |
|---|---|---|---|---|
| Serene® | 20.49 | 47.73 | 19.19 | 36.11 |
| Standard foam A | 23.15 | 54.08 | 24.46 | 40.42 |
| Standard foam B | 21.78 | 64.31 | 24.81 | 41.80 |
| Memory foam | 21.55 | 50.40 | 24.03 | 37.71 |
Side sleeping puts the most pressure on the shoulder, and that's where Serene stood out: average shoulder pressure was 20% lower than memory foam. The gap is smaller here than on the back, and memory foam held its own on peak pressure, which is fair to point out. Memory foam is good at side sleeping. Serene was simply a little better on every measure.
A note on what this does and doesn't mean: these are tests on a 2" layer of foam, not on a finished mattress, and comfort is personal. But they line up with what we hear from customers, which is that the bed feels supportive without pressure building up at the shoulders and hips.
Does Serene Foam Sleep Hot or Get Hard in the Cold?
Summary: Serene feels the same in a cold bedroom as in a warm one, which memory foam doesn't. It also released heat faster than memory foam in testing. It isn't a "cooling" foam, though, and we won't call it one.
Why memory foam gets firm in the cold
Every foam has a temperature below which it starts to stiffen, called its glass transition temperature. Memory foam is designed with that point close to room temperature on purpose, because that's how body heat softens it and creates the molding feel. The flip side is that the colder the room, the firmer memory foam gets until it warms up.
Carpenter measured that point for several foams:
Why memory foam gets firm in the cold
| Foam | Temperature where it starts to stiffen |
|---|---|
| Memory foam (first generation) | 0.8°C |
| Memory foam (newer generation) | −20.5°C |
| Serene® foam | −51.6°C |
| Standard polyurethane foam | −52.9°C |
| High resilience (HR) foam | about −59°C |
Serene's stiffening point is far below anything a bedroom will ever see, so it feels the same whether your room is at 17°C or 23°C. Carpenter describes its temperature sensitivity as undetectable in normal use.
Why that matters in Canada
A lot of Canadians turn the heat down at night in winter, and older homes and basement bedrooms run cool. On memory foam, that can mean a bed that feels noticeably firmer when you first get in. Serene doesn't have that problem.
It also matters before you ever sleep on it. A mattress in a box that sits in a delivery truck or a cold hallway in January needs to soften and expand once it's inside. Carpenter notes that Serene is easier to handle and deliver in cold climates than memory foam, and that it responds immediately at any room temperature.
What about heat?
Memory foam has a reputation for sleeping hot because it holds onto body heat. In Carpenter's test, foam samples were warmed for about three hours, then left to cool:
- In the first 30 minutes, Serene released heat 18% faster than memory foam (0.396°F per minute vs. 0.336°F).
- Over the first hour, it was 8% faster (0.348°F vs. 0.321°F per minute).
That's a real difference, but a modest one. Serene doesn't have gels, phase change materials or any active cooling, so it's more accurate to say it doesn't trap heat like memory foam than to call it a cooling foam. If you sleep very hot, what's underneath matters more. The open coil layer in our Hybrid moves far more air than any foam can.
Is Serene Foam Bouncy or Slow?
Summary: It sits in the middle. Serene recovers about four times faster than memory foam, so moving around is easier, but it still absorbs more motion than standard foam.
The standard way to measure this is a ball rebound test (ASTM D3574, Test H): a steel ball is dropped onto the foam and the height it bounces back to is measured as a percentage. The higher the number, the springier the foam.
Is Serene Foam Bouncy or Slow?
| Foam | Ball rebound |
|---|---|
| Memory foam | About 5% |
| Serene® foam | About 20% |
| Standard polyurethane foam | About 45% |
In practice, this explains one of the biggest complaints about memory foam. That stuck-in-sand feeling when you try to roll over comes from its very slow recovery. Serene pushes back sooner, so changing positions takes less effort, which matters most for combination sleepers who move through the night.
It's still well below standard foam, which means it dampens a lot of movement. If your partner shifts or gets up, less of that energy travels across the bed. Memory foam is still the champion of motion isolation, and if that's the only thing you care about, it's hard to beat. For most people, Serene's balance is the better trade.
How Durable Is Serene Foam?
Summary: Very. In Carpenter's fatigue testing, Serene matched high-density memory foam for durability while being up to 40% less dense. In our own testing, the Cozey Foam Mattress softened less than 6% over the equivalent of 15 years of use.
Why density usually decides durability
With memory foam, durability mostly comes down to density. A low-density memory foam (around 1.5 lb/ft³) breaks down and develops body impressions quickly. To get memory foam that lasts, you need high density, around 4 lb/ft³, which makes it heavier and more expensive.
Serene breaks that rule. At 2.5 lb/ft³, Carpenter's constant force pounding test (ASTM D3574, Procedure I3) put it in the same top durability tier as 4 lb high-density memory foam, and well ahead of medium-density memory foam at the same 2.5 lb density.
The test results
The test results
| Test | What it simulates | Serene® result |
|---|---|---|
| Constant force pounding, 12,000 cycles | Years of repeated body weight | Less than 2% height loss, about 7% firmness loss |
| Compression set, 75% and 90% | Being squeezed flat and held there | 2.3% permanent height loss |
| Wet heat compression set, 50% | Compression in heat and humidity | 4.6% permanent height loss |
| Walk-in oven aging | Long-term heat exposure | 0.03" height loss (vs. 0.09" for standard foam and 0.78" for a high resilience foam) |
What that means for a Cozey mattress
The comfort layer is usually the first part of a mattress to wear out, because it's closest to your body and does the most work. That's why we wanted a top layer that holds its shape. In our durability testing simulating 15 years of nightly use, the Cozey Foam Mattress lost less than 6% of its firmness, and both of our mattresses are backed by a 15-year limited warranty that covers indentations of 1" or more.
Is Serene Foam Safe?
Summary: Yes. Serene is CertiPUR-US® certified, and every foam in Cozey mattresses is too. Cozey mattresses also meet Canada's mattress flammability standard.
CertiPUR-US is the independent certification program for flexible polyurethane foam used in bedding and furniture. Certified foams are tested by independent labs and must be made without ozone depleters, PBDE flame retardants, mercury, lead and other heavy metals, formaldehyde, or phthalates regulated by the U.S. Consumer Product Safety Commission. They also have to meet low VOC emission limits for indoor air quality.
As a finished product, our mattresses meet the Canadian flammability standard for mattresses (CAN/CGSB-4.2).
Like any new foam mattress, you may notice a light "new foam" smell when you first unbox it. It's harmless and usually fades within a day or two, faster if you open a window.
What Are the Downsides of Serene Foam?
We chose Serene, so we're not neutral. Here's where it falls short.
- Less of a deep hug than memory foam. If you love sinking into your mattress and feeling held in place, Serene will feel more supportive than you're used to.
- Memory foam still isolates motion best. Serene absorbs a lot of movement, but memory foam absorbs more.
- It isn't a cooling foam. It releases heat faster than memory foam, but there's no gel or cooling technology in it.
- Most of the data comes from Carpenter. The lab results in this article are the foam maker's own testing on foam samples. They're detailed and consistent with what we see, but they aren't independent tests of a finished mattress.
- It's one layer of the mattress. A comfort foam is only as good as what supports it. The same Serene layer feels different over dense foam than over pocket coils.
Who Is Serene Foam Right For?
Who Is Serene Foam Right For?
| Serene is a good fit if you... | You may prefer something else if you... |
|---|---|
| Like the contouring feel of memory foam but not the heat | Love a deep, slow sink and feeling held in place |
| Feel stuck on memory foam when you roll over | Want the absolute maximum motion isolation |
| Sleep on your side or back, or switch between positions | Want a very bouncy, latex-like feel |
| Keep your bedroom cool at night | Need active cooling for very hot sleep |
| Share a bed and want some motion isolation without the quicksand feel |
How Cozey Uses Serene Foam
Summary: Both Cozey mattresses use a 2" Serene® comfort layer on top. What's underneath decides how the mattress feels.
When we developed our mattresses, the goal was a bed that the largest number of people would love. That pointed us to a medium-firm feel and to a comfort layer that gives people the contouring they like about memory foam, without the heat, the stuck feeling or the stiffness on a cold night. Serene checked every box.
How Cozey Uses Serene Foam
| Cozey Foam Mattress | Cozey Hybrid Mattress | |
|---|---|---|
| Comfort layer | 2" Serene® foam | 2" Serene® foam |
| Transition layer | 2" high-density foam | 2" high-density foam |
| Support | 6" high-density foam | 6" individually wrapped pocket coils (1,200 in a Queen) + 1" high-density base foam |
| Height | 10" | 12" |
| Firmness | Medium-firm, about 5.5 to 6 out of 10 | Medium-firm, about 6 to 6.5 out of 10 |
| Price (CAD) | $650 (Full), $695 (Queen), $895 (King) | $850 (Full), $895 (Queen), $1,095 (King) |
Over dense foam, Serene feels close and cradling, with very little bounce. Over pocket coils, it feels a bit firmer and more lifted, and the coils let more air move through the bed. Both are made in Canada, come with a 100-night trial and a 15-year limited warranty, and ship free across Canada.
If you're deciding between the two, our guide comparing the Cozey Foam and Cozey Hybrid mattresses goes through it in detail. Or shop the Cozey Foam Mattress and the Cozey Hybrid Mattress.
Sources
- Carpenter Co., Introducing Serene™ Foam, technical presentation, M.H. Reinhart Technical Center (pressure mapping, temperature sensitivity, heat dissipation, rebound and durability testing)
- Carpenter Co., Family of Foams sell sheets, including the Serene® foam specification sheet (rev. June 2023)
- Carpenter Co., The History of Carpenter
- Cozey internal durability testing of the Cozey Foam Mattress