spa sensations and night therapy

Whats your opinion on these mattresses? how do they compare with Novaform/sleep innovations?

Hi Sleepseek,

Both the Spa Sensations and the Night Therapy are made by the same company Zinus which means they would tend to have similar value (lower price would mean either less material or lower quality materials etc). In terms of comparing them to the Novaform … they would probably have similar value here as well. A true value comparison can only be made though if the specifics of the foams used in each mattress are known which they don’t have listed. For me … knowing the materials used in a mattress are far more important in determining value than the brand name that is attached to it.

Most “discount” brands sold through big box stores are fairly competitive in value. They are all likely 4 lb memory foams at most … but this is often not specifically shown on the descriptions and some of them could well be less in which case I would pass them by completely. I personally would never buy memory foam without knowing the density of the foam and if 2 memory foams are the same density and thickness and both manufactured by a known and CertiPur manufacturer, then IMO the comparative value of the can then be determined by price. While this wouldn’t take into account the difference in feel between different memory foams or the non memory foam layers, it is the only way to really compare value based on the durability of the foam and its tendency to soften and change over time.

I also believe that Aerus memory foam in the 4 lb version is a great “budget” choice as it is a known foam with good characteristics and is available in many budget mattresses. Overall though … in terms of a value comparison … foam density of both the memory foam and the polyfoam underneath it is the most “accurate” means of comparing quality and price (along with knowing the foam is produced by a known manufacturer who is CertiPur certified which both Sleep Innovations (Novaform) and Zinus are).

When you are buying a budget mattress online from a big box store with a great return policy … you are usually buying a mattress which will have low/mid quality materials that are designed to fit “average” preferences. None of these will have the durability or feel of a higher quality mattress (at least for long) and because every type of memory foam made by different companies has different characteristics (density, temperature sensitivity, response time, breathability, etc.) and is used in different combinations of layering … it is usually best to just buy the one that seems to be closest to what you need and then trust the return policy if it doesn’t work out. The return policy is “traded” for actually being able to know through testing if the mattress will be “perfect” for an individual. Knowing the density of the foams used at least will give a good indication of how long it will take for the foam to begin degrading.

Most of the discount mattress manufacturers at these stores will have similar “value” in terms of actual cost of material … but each mattress they make may have very different feels. They also may put their “value” in different areas of the mattress. Since the “weak link” in a mattress is usually the comfort layers, then it makes sense to me to put particular emphasis on the quality of the materials used here and in the ticking … especially with memory foam which will tend to soften and degrade over time anyway (faster with lower quality foams). An important part of value IMO is also knowing how a mattress will feel for each individual and this is not really possible when buying a mattress online, especially with memory foam (unless you’ve tried the specific mattress you are buying or a mattress with very similar materials and layering). Overall, I would also tend to buy the thinnest and highest quality memory foam layer that was likely to suit my needs (since IMO many memory foam mattresses have too much memory foam in them to cater to the widespread consumer belief that “more is better” and sell more foam).

If I was buying a “discount mattress” online … I would make sure that the foam specs were known … especially of the memory foam density (even though the support foam and the layering will also make a big difference in how it feels and performs for each individual) and then just buy the one where the thickness and quality of the memory foam seemed closest to what I needed for my weight and sleeping positions. For those who want to know ahead of time how it will actually feel … then personally testing a mattress (or mattresses that use similar materials and layering) becomes very important and the only way to know for sure or even “guess” about an online purchase. If you have tested a mattress with a specific layering that is close to what you like and need … then it is easier to “duplicate” but even here the different formulae used in different memory foams will create a different feel. Polyfoam of the same density and ILD will be much more similar between different foam manufacturers. Memory foam, even in the same density between different manufacturers and or between different formulae made by the same manufacturer will have much wider differences in how they respond and feel.

For an online “budget” purchase I would base my choices on knowing the materials (not the mattress brand), compare the relative quality of the memory foams, the layer thicknesses and construction, the ability to “customize” the mattress after you have bought it (layers that can be re-arranged or exchanged), and the return policy and the costs and effort involved in returning it. In addition to this I would choose a mattress that seemed most similar to a mattress that I liked in field testing. Beyond this … I would just “pull the trigger” and roll the dice :).


Thank you!

Re Aerus memory foam. I find very few reviews on it online. Do they manafacture for other brands? Is there more data on this than I can tell? Why do you recommend it? Thank you!

Hi Sleepseek,

Aerus memory foam is made by a company called Foamex/FXI. They, in partnership with Recticel and Beamech (who makes foam pouring equipment) developed a new foaming process called VPF (Variable Pressure Foaming). They hold the North American rights to this process while Recticel holds the European rights. This process … based on my research and that of others I respect produces a higher quality foam than other methods.

FXI manufactures a very high quality foam called Sensus which is a slower rebound memory foam but the technology also allowed them to produce a more open celled and breathable foam called Aerus. While there are also companies that are using various methods to produce more open celled foams through various chemical or mechanical processes … I believe that the VPF foaming method results in a more breathable and higher quality memory foam. It is also more enviornmentally friendly than other processes used for polyfoam and memory foam.

Aerus goes by many other trade names just like almost all other foams produced by foam manufacturers. It is sometimes very difficult to “track down” which tradenames refer to which foam since a company can just make up a name so that it seems that their foam is exclusive. Each foaming company can also make custom formulations of any foam they make for the specific requirements of a mattress manufacturer who uses their foam. To complicate matters even more … the companies who created VPF foaming can also license the rights to this technologies to other companies who then produce foam under their own names which in turn is also re-branded by mattress manufacturers who buy foam from them.

My “educated” guess is that Cool Touch and Cool Comfort are also Foamex products although there are many more. Foamex polyfoams and memory foams are used in many mattresses under many different names. Anatomic Global also uses Foamex foams.

While there are certainly other high quality foams made by many manufacturers … based on my own research Foamex is “slightly ahead of the pack”.


So it should be cooler than other memory foam? I also noticed the mattresses are lighter, doesn’t heavier usually mean better - higher density?

Hi sleepseek,

Yes … even though this is relative to other memory foams as even “cool” memory foams tend to be hotter than other foams.

Yes, all other things being equal … the density of memory foam is a major part of its quality. All brands of memory foam though can be manufactured in any density so Aerus could be made as a 3 lb, 4 lb, or 5 lb version as well as various “customized” densities. I would certainly avoid any 3 lb memory foam whether it was Aerus or otherwise but if I had a choice between a 4 lb Aerus and a 4 lb “other” memory foam … I would likely choose the Aerus … unless there was a compelling reason to choose differently because of other factors that were part of the mattress (other layers, ticking etc).


My question is, does the overall weight of the mattress have any bearing on the quality of the mattress?

Hi sleepseek,

The overall weight has little to do with the quality of the mattress … only the density of the polyfoam or memory foam layers which will tell you the quality of that layer. The quality of the comfort layer is the most important as this is the part that is the weak link in most mattresses. The overall weight of the mattress is more about the combination of materials used and will tell you little about the quality of each layer.

For example a queen size mattress with 3" of 5.5 lb memory foam (high quality memory foam) over 6" of 2.3 lb polyfoam (high quality polyfoam) would be a good quality mattress. The weight of the comfort layer would be 45.8 lbs. The support layer would be 38.3 lbs. and the total mattress weight (excluding the ticking) would be 84.1 lbs.

Another mattress that had 4" of 3.5 lb memory foam (low quality) over 9" of 1.8 lb polyfoam (the minimum that would normally be considered as “good quality” in a support layer outside of lower budget mattresses) would be a lower quality mattress. The weight of the comfort layer would be 38.9 lbs. The support layer would be 45 lbs. The total mattress would be 83.9 lbs (again excluding the ticking). They would be identical in weight but the first would be much higher quality than the second.

A mattress with 4" of 4.5 lb memory foam over 8" of 2.0 lb polyfoam would weigh 56.3 lbs plus 44.4 lbs or a total of 100.7 lbs. This mattress would be “in the middle” in terms of quality. If you only needed 3" of memory foam with a higher density for good pressure relief … then the thinner layer of higher quality memory foam would also be much better for alignment and more suitable overall than thicker layers of softer lower density memory foam. A higher quality support layer also wouldn’t need to be as thick.

So overall … the total weight of a mattress will not say much about the quality of the mattress because high quality in different materials has a different density between materials.