Phase changing memory foam

What do you know about phase changing memory foam and technogel memory foam? Separately and compared to each other. Is one better than the other, which sleeps cooler, which has been around longer?


Hi vici0usx,

Your question may be a little more complex and cover more territory than you realize :slight_smile:

One of the things I have been working on for many months is to compile some good and accurate information about the many types of gel foams (gel memory foam and otherwise) so people have a reasonable way to compare them. It’s unfortunate that most of the information about them is mostly marketing and little of it is fact based but I have been fortunate to have a lengthy conversation with one of the top foam chemists in the country about this foam category and with others that have good experience or knowledge as well. Over time as new information becomes available I will edit the various posts around the forum with updated information and update some of the earlier information about gel foams but this will be a gradual process as more information becomes available because my research is still far from complete and the gel foam category is changing and evolving as new foams and technologies enter the market. The gel foam category (particularly the gel memory foams) have not been around for long enough to really know their “real life” performance or durability over the longer term. The exception is buckling column gel materials (which use a stiffer gel and have columns which “buckle” under pressure) such as intelligel or orthogel (and also see post #7 here) which have been used in consumer mattresses for a little over a decade.

For now though … you will find some technical and safety information about the soft solid elastomeric gels (such as Technogel) in post #4 here. Note that they are not memory foam although they do have some visco-elastic properties.

You can read more about the three main cooling technologies (thermal conductive materials, phase change materials, and ventilation/humidity control) in post #9 here and at the end of post #4 here.

Finally you can read a brief description of the different types of gel foams more commonly available (and this will be updated as newer types of gel memory foam and more detailed information about each type becomes available) in post #2 here and an overview about gel materials in post #8 here.

Gel materials themselves (soft solid materials) in other industries have existed for a long time but their use in mattresses only goes back in the range or about 5 years or so and the gel memory foams and the gel category itself was made much more popular when Serta introduced the iComfort in early 2011 and became a big marketing success which was copied by most other manufacturers. It also led to sales that helped propel Serta past Sealy to become the largest manufacturer in the country.

The soft solid versions of pure gel such as Technogel are typically used in thinner layers because they have a very high compression modulus and are generally too firm for most people in thicker layers. They are thermally conductive and because of their high gel content they work well for this but they lack ventilation and humidity control so they usually come with surface modifications both for comfort and performance and to improve ventilation. A forum search on Technogel (you can just click this) will bring up quite a few more posts that have more information about them and includes some feedback from members.

Kingsdown (in their Blutek line) and Sherwood bedding (in their Evosleep line) are a couple of other manufacturers that use soft solid gels in some of their mattresses.

The gel foam segment is still dominated by marketing information, and “me too” designs and a fair bit of hype though which in most cases has some partial truth but is not especially informative or accurate about it’s benefits or the specifics of the materials.

Overall though … gel memory foams tend to sleep a little cooler than “regular” memory foam although the benefits often don’t last over the course of the night (again depending on the specifics of both), be similar in durability compared to the same density of “regular” memory foam (except for those that use larger “chunks” that can migrate out of the material easily), can add some extra support to the memory foam, and can add some cost to the base material as well. Over time and as new generations and variations become available the performance benefits of these types of foam appear to be gradually improving but it’s difficult to know how much is hype and how much of the information is reliable outside of retailers or manufacturers that will give you accurate “real life” information based on their experience (even if all the technical specifications outside of density aren’t available). There are also many differences between different gel memory foam materials in terms of density, formulations, performance, and cost and in some cases some of the better quality or higher performing versions that use higher percentages of gel or more costly manufacturing methods or compounding formulas and have greater “real life” performance benefits but are more costly can be “overwhelmed” by similar looking but much lower cost gel memory foams that don’t perform as well or don’t have the same benefits as their higher cost competitors.

This is similar to “regular” memory foam where there are many lower cost and lower density “cheap” memory foams that are being advertised as “just as good” as higher quality and more costly versions of memory foam that have greater durability or performance but of course they aren’t and in many cases consumers have come to believe that “all memory foam is alike” when of course it isn’t. The same is generally true of the emerging group of gel memory foams as well where similar looking products can have a range of differences that aren’t always obvious.


Hello again. I hope I am posting this in/on thr right thread! It relates generally to cool-gel products, and specifically to a product currently being sold at COSTCO. (No, please don’t stop reading yet!)

My husband and I are both super hot sleepers. In fact, it’s the main reason he brought up the subject of our getting a new bed. But, about a year ago, I purchased through an online catalog company, some very inexpensive, small cool-gel pads. The smallest ones can either be slipped under your pillowcase or you can lay your head on it directly. A slightly larger one is for laying under your torso. They are definitely cool when first in use, but ultimately they draw one’s own body heat into them and end up feeling as warm as a heating pad! That’s when they get tossed on the floor!

I also bought (just prior to finding your fantastic website) two pillows that are either memory foam or some sort of smelly faux latex (we’re still airing them out after a week!) that have some sort of cool-gel layer on one side. We tried using them the other night, but the chemical smell prevented either of us from using them long enough to determine if they, too, will heat up after awhile. But I went to reviews of the pillows (unfortunately, I did this after the fact

Hi Cyd,

Phase Change Material (PCM) is different from Gel, but is included in mattresses for the same reason: to absorb excess heat from the sleeper.

PCMs have been around for a long time now - you’ve probably seen those crystallizing heating packs that get warm when they solidify. The principle is that when a material changes state, heat energy is either stored or released. Generally, when a substance changes from a liquid to solid it releases energy, as with the heating packs. The reverse is also true.

Mattresses make use of the solid-to-liquid phase change to absorb heat - don’t worry: PCMs in mattresses are “micro-encapsulated” so they do not leak out when in liquid form.

Okay - so how does this help you? Well - a PCM can absorb only so much heat before it becomes exhausted. This means that you’ll feel cooler earlier in the night, but will eventually warm up and start sleeping hot again. Gel is much the same.

The reality is that any heat-sink material must be combined with something else - a good moisture-wicking cover, airflow layers in the mattress, etc. In our experience, breathe-ability provides the most benefit.

Happy sleeping!


Thank you! Don’t know what happened to that message of mine; it was much longer … But then, I tend to ramble! Went on to ask specifically about a mattress being sold at (gulp!) COSTCO. The Spring Air back supporter with Gel. Was wondering about their “stuff” …

“premium Layers”. (Comfort layers?)
The latex is .5 Talalay (BTW: Can you give me an idea as to how that word is pronounced? Which syllable is accented?)
Then .75 CertiPUR-US Comfort foam (seems rather vague!)
.5 Gel infused Memory Foam

Support Core
7" CertiPUR-US Certified Plant Based Foam (uh, what plant!?)
1.5 Stabilizer Foam (again, really vague)

I’ve read and learned a lot on this site (thank you to one and all!), but hubby saw this & got all enthused about it, then got upset w/me when I turned my nose up to it. I’d like to be able to better explain to him why I have concerns about the product. Then again, maybe I should’ve have concerns. COST:$1700 for King set. Can’t find info on mattress return policy, but overall COSTCO has very good customer service & return policy. Again, thanks for the help. Cyd

Hi Cyd,

[quote]“premium Layers”. (Comfort layers?)
The latex is .5 Talalay (BTW: Can you give me an idea as to how that word is pronounced? Which syllable is accented?)
Then .75 CertiPUR-US Comfort foam (seems rather vague!)
.5 Gel infused Memory Foam

Support Core
7" CertiPUR-US Certified Plant Based Foam (uh, what plant!?)
1.5 Stabilizer Foam (again, really vague)[/quote]

Most of this information has little meaning and what you need to evaluate a mattress is the thickness of the layers along with the foam density in the case of polyfoam or memory foam and the type and blend of any latex. The only part of this that they disclose is the talalay latex (which is a good quality material and probably blended) and the thickness of the 1/2 gel memory foam layer (again with no density information).

The latex in this mattress is only 1/2" so it’s more for label copy than anything else.

Besides the latex and gel memory foam, the rest of the foam materials in the mattress would probably be polyfoam (the comfort foam, the “plant based” foam, and the “stabilizer” foam) and the density of each of these layers is the single most important factor in evaluating their quality and durability.

In most cases … Spring Air is one of the major brands I would tend to avoid because they don’t disclose the information you need to make an informed choice or meaningful comparisons. When you are able to find out (usually through “alternative sources” or some frustrating research that usually leads to dead ends) you will usually discover that the quality/density of the materials is lower than many other mattresses with better quality and value. As you can see in the guidelines here … I would avoid buying any mattress where you aren’t able to find out the information you need about the quality of the materials inside it.

You can read a little more about “soy foam” or other so called plant based polyfoam or memory foam materials in post #2 here. They are just a version of polyfoam or memory foam and the density can be directly compared to “non plant based” foams.

You can also read more of my thoughts about buying from Costco in post #4 here.

Talalay is pronounced tah lah lay with the emphasis on the first syllable (you can hear it pronounced here)

Hope that helps :slight_smile:


Like Cyd, I too almost fell for the Spring Air demo at Costco. Same specs as Cyd listed. :ohmy:

Fortunately, I found this site and visited my “local” mattress shop, Gardner Mattress in Massachusetts.
Gardner Mattress

Now, I want to double check that I am doing the “right” thing as prescribed by your site.

I got a little nervous because the mattress I settled on has NO latex, and I had wanted latex. If there’s one thing I have learned here is that Latex is good! I went into the store wanting a two-sided mattress, one that I could flip almost by myself.

So, what are your thoughts on a two-sided innerspring mattress with a cotton damask cover, lace-tufted and quilted, with 1 1/4" of foam (polyfoam, 4lb density) which according to the salesman wears better than a one-sided latex construction. Plus it has great handles for grabbing & flipping.

For those wondering, the Queen Sacro Tuscon quilt set (mattress & box) sells for $1429 (with a 10% discount). Gardner is adding a double reinforced edge for no added cost. (The demo deal on a Spring Air at Costco was $1500.) This mattress will be used in a young adult’s room who is off at college, and in the meantime an infrequently used guest room. After graduation though it might get a lot of use! My son is over 6’4" and under 200lbs. He generally likes a softer bed and this new one will be on the firmer side. If he really can’t stand we’ll supplement it with a topper.

Am I missing anything? Do options exist for two sided medium firm beds with long lasting latex? Those with latex at Gardner were one sided only (except a 6" mattress which was solid latex). Would that be a better choice?

Thank you for this site! And I hope to hear what folks have to say.

Hi Coneflower,

I don’t know all the details of your mattress (type of innerspring and all the layers and components) but on the face of it you are certainly looking at a high quality mattress. 4 lb polyfoam is a very uncommon material and ultra high density polyfoam (such as Energia or other similar materials) approaches latex in its performance and durability and I would agree that a two sided mattress using it can have similar or in some cases even better durability than a one sided latex mattress (you can see some of the factors involved in the durability of a mattress in post #4 here).

I believe that Gardner mattress would give you accurate information about their materials and they are an 80 year old company that has built a great reputation for building high quality mattresses that use many hand building methods that are missing from most mainstream mattresses that are currently made. You can see an interesting video here about them that will give you a good sense of who they are and what goes into their mattresses.

If your son has carefully and objectively tested the mattress for PPP (Posture and alignment, Pressure relief, and Personal preferences) so you have confidence that the mattress is suitable for his needs and preferences … and you have made some good comparisons with other mattresses … then I certainly wouldn’t hesitate to purchase a mattress from them as long as the purchase was the best match for your personal value equation.

You can see some examples of two sided latex mattresses made by one of our members that have good quality and value here as a value reference. All latex in a suitable construction and firmness level for the person is durable and long lasting but even with latex a two sided mattress will last longer than a one sided mattress that uses the same type and quality of materials. The tradeoff for a two sided mattress is that you can only use relatively thin layers on each side of a support core in the middle or you would be risking alignment and there are more design possibilities in a one sided mattress where the firmer support core is on the bottom and then you can add thicker layers in various thickness and firmness levels on top of it without risking alignment issues when the thicker softer layers are on the bottom.

Once you have eliminated all the worst choices, there are no weak links or low quality materials in any of the mattresses you are considering, and you are looking at all good options … then there are no longer any “better or worse” final choices except based on all the objective, subjective, and intangible parts of a mattress purchase that are most important to you.


The sales rep at Costco couldn’t answer any of my questions re: specifics on materials used. she referred me to the number on the flier. Called it. No one there could provide info. They referred me to yet another number. Woman who answered phone was pleasant enough until I told her why I was calling. Then became suspicious & asked me if I worked for a mattress co.! I explained who I was & why I was calling & she told me woman I needed to talk with wasn’t in, but if I left my phone #, she’d have her call me. I gave her my e-mail address & told her to just have the woman e-mail me. Never heard from anyone. Too bad; it actually looked and felt like a pretty decent mattress set, & the price was certainly right. Who knows, maybe the answers to my questions would have been acceptable to me & I would have bought the set. And no one beats COSTCO’s return policy!

We ended up purchasing a king set manufactured by Southland & branded by Sharper Image. Pricey, but at $3000, still not as much as we paid 11 years ago for our then top of the line king Select Comfort bed. It has individually wrapped coils that are tiered at different heights for support areas (shoulders, hips) with foam support layers and topped off with about 4" of Talalay latex. We got the firmest one. Had it about a week now & the jury is still out. Hubby thinks it may be a little too firm, whereas I have concerns it may not be firm enough! Also, I love the feel of the latex, & I know the various foam layers help with the motion transfer issue, but I can still feel my husband bouncing around if I’m not in a deep sleep. I have noticed I am waking with little or no hip pain (with old bed I couldn’t stand up straight in morning!) and hubby says he is no longer waking with leg pain. All in all, I think we did the right thing & this mattress set is going to work out for us. But, of course, only time will tell!

Hi Cyd,

Thanks for the feedback and I hope you’re happy with your new mattress :slight_smile:

Just for reference (and of course if you know them) it would be helpful for others if you could list all the layers of your Sharper Image so that others that are interested can also make some meaningful comparisons with other mattresses they are considering.

There is much more information in post #2 here and the posts it links to about the many different types of gel materials including the different types of gel memory foams.


This is a follow-up to my earlier post. I am hoping the info will help others as they navigate the mattress buying decision.

We bought a queen-sized semi -Sacro mattress from Gardner Mattress. The mattress will be used in an infrequently used guest room and probably when my son returns from college. The total was $1,488. They removed the old mattress & box for $20.

These are the specs (a correction to my earlier post, I took a lot of notes so this list might be redundant with itself):

Queen size “Semi -sacro” two sided mattress & box spring
non-pocketed coils, hand tufted springs with cotton
3 to 4 layers of felt
2 layers of cotton
hand compressed tufted
3/4" poly-foam each side (weight 1.8lbs) (this was not easy to ascertain!)
metal gauge - 13 (I was advised this was not important, but they reinforced the edges of the mattress for no charge, which gives more strength to the edge of the bed, for when sitting & putting on shoes)

It’s a firm mattress but not their firmest. We also considered their latex mattress (one-sided) but that was over $800 more. When our master mattress “wears out” (a Shifman) I will consider another Gardner Mattress.

I would be interested in feedback about what the weak links are in this mattress.

I learned a lot this time around and I am sure there was more due diligence to do. I am glad though I avoided a costly Costco & “S” brand mattress mistake! Thank you for all your help.

PS - photos from the showroom of a mattress similar to ours.

Hi Coneflower,

It’s nice to see a manufacturer that still makes a traditional two sided innerspring / box spring mattress that uses tufted cotton in the padding. This is somewhat of a lost art in today’s market and they are generally only made by smaller manufacturers such as Gardner.

Normally a thin polyfoam quilting layer that is “around an inch or so” or less isn’t a weak link in a mattress even if the polyfoam is lower density and I usually don’t worry too much about tracking down the density of the quilting form or a single very thin layer but in your case the quilting polyfoam is 1.8 lbs which is good quality and unusual to see.

These types of mattresses are very durable … although they are also firmer than most mattresses that use foam layers for the padding.

There are no obvious weak links in this mattress and it will last for a very long time and certainly much longer than most innerspring/polyfoam mattresses that are sold today. :slight_smile:


PS: I hope you don’t mind that I switched your post to its own thread so that it would be easier to find for others who are considering this mattress as well and it wasn’t really connected to phase changing gel which was the topic of the other thread.