Memory Foam Buyer's Guide
Part 1 - Brief History Of Memory Foam And Why Not All Memory Foam Created Equal -- Some Memory Foam Just More Comfortable Than Others And Sleeps Cooler
After memory foam was developed as part of a NASA project, some saw the promise of memory foam for use in the medical industry to relieve pressure sores. Over the years, memory foam was shown to be unique in the way it responded to temperature and also in its ability to spread pressure over a greater surface area (and thereby reducing pressure points significantly). While the initial version of the foam developed for NASA (called T-Foam) did have a great deal of promise as a bed topper or wheel chair cushion material, it did have issues with wear over time. This first generation of material wasn't very durable, and would often compress or crack over time.
The first company to realize the potential of memory foam for the consumer market was Tempur-Pedic ®. They had worked on creating their own version of memory foam, and developed foam they called Tempur ®, that was much more durable and still had the pressure reducing benefits of memory foam. Initially, this Tempur ® foam was used in medical settings, but soon they began to hear that patients who used the foam slept better, had less back pain, and felt more refreshed in the morning. A light bulb switched on over someone's head in Sweden, and Tempur-Pedic ® began to sell the products to consumers.
Due to its origin as a medical device, Tempur ® foam was very expensive, and has stayed that way to this day. After a few years on the consumer market, other foam manufacturers saw the potential of memory foam and began to produce their own memory foam product lines. Because these manufacturers came from the consumer foam industry, rather than the medical industry, their cost structure for memory foam was much lower and they priced their products at a fraction of the Tempur ® foam. As the years went by, memory foam became more and more popular, and now manufacturers all over the world are making their versions of memory foam.
Memory Foam Really is Unique, and Has Unique Benefits
While specific types of memory foam do differ in the level of comfort they offer, looking at the broader picture, overall memory foams in general are unique in many ways versus other comfort products used in bedding.
I've looked at many bedding materials, from latex to cotton to wool. And nothing compares to memory foam in the way it conforms to your body and reduces pressure points.
Why is memory foam so different? There are a couple of reasons that memory foam is so unique.
First is the way memory foam cells deform when weight is applied. Unlike standard foams that compress and want to spring back to their original shape immediately, memory foam cells (open cell foam, which means the individual cells in the foam have holes in them) compress fully and spread their air pressure to adjoining cells.
This spreads the pressure through a greater number of cells of the memory foam - which decreases the pressure you feel in the cells of the memory foam that you are laying on. This accounts for the way that memory foam actually reduces pressure points.
This ability of memory foam to deform also allows it to really conform to your body's shape and weight bearing areas, thereby reducing these pressure points. No other material has this ability to shape to your body - this is unique to memory foam.
However while memory foam's characteristics offers unique comfort benefits, you wouldn't want an entire mattress made strictly of memory foam. Memory foam is too soft a material and isn't meant to be supportive. So it works best when layered over a firm, supportive material.
That is why you will mainly find memory foam as a 2" or 3" topper to be used on your existing, firm mattress, or as a 2" or 3" topping layer in a new memory foam mattress.
Second, memory foam is temperature sensitive. Which means that at lower temperatures it is firmer (more viscous), and at higher temperatures it is softer and more conforming (more elastic). This is the reason memory foam is known as visco-elastic memory foam.
This temperature sensitive quality accounts for the melting feeling that you get lying down on memory foam, and also accentuates the custom molding affect of the foam. Certain memory foams, such as Tempur-Pedic's ® Tempur ® foam, are fairly temperature sensitive and can get firm even near room temperature.
The memory foam we have used in our toppers and mattresses, in contrast, have a broader range of temperatures where they stay nice and soft, so they are soft and responsive at common room temps.
Not All Memory Foam Is Created Equal, Though -- Some Are Just More Comfortable Then Others And Sleep Cooler
What you need to remember is that not all memory foams are equal. They differ a great deal in quality - density, hardness or softness, response to temperature, and also durability and longevity.
Just by looking at the technical specs, though, of a particular memory foam, you can't determine the overall comfort of that memory foam. I hear from people all the time that get immersed in the technical details -- they want to know the different densities and ILD (or IFD -- which is a measure of how hard the foam is) -- as though these specs are they keys to buying a memory foam topper or mattress.
And while density and ILD do carry some import -- I've found memory foams 4 lb density and higher offer better support and comfort than less dense memory foams, and having a low ILD means the memory foam has a soft feel -- I've seen in my real world testing that memory foams with identical specs for density and ILD got very different ratings for overall comfort.
That is why it is really important to understand not only the quality issues that go into making a memory foam, but also why I focus so much on our products on real customer reviews to gauge how comfortable a particular type of memory foam or layered memory foam mattress configuration really is.
Just a quick example to illustrate this. In a comparison test I did to pick our latest memory foam mattress (of 6 different memory foam mattresses), there was a gaping difference in comfort ratings by our testers of the lowest rated mattress and the top rated (which is now the mattress we carry).
Again, these mattresses had almost identical specs in terms of density and overall construction, but the lowest had only 75% say they would recommend it to a friend, while our 10" Memory Foam Mattress had 96% saying they would recommend it.
So not all memory foam is created equal -- some really do offer a different level of comfort, and only by looking at real world results, not specs, will you be able to get a feel for the comfort of a particular type of memory foam.
In addition, some memory foam has a much more open cell structure, which allows better airflow so that this latest generation of memory foam sleeps cooler than less expensive, standard memory foams.
With all the different memory foams out there these days, it can get confusing how to sort through the different options and get the right memory foam mattress or topper for you. In the next section, I will go in-depth into how to choose between different memory foams and explain the criteria I use when assessing different memory foams to use in our products.