Foam Encapsulated Pocket Springs (FEPS)

Foam encapsulated pocket springs is a term you may see on many different products as the merge between traditional and more modern mattress materials takes place.  There is no one type of FEPS and so again a clear explanation of what FEPS are and how they behave is needed.

FEPS are simply pocket springs that are encased in a foam box.  They are encased in a foam box to ensure they keep their position, don’t migtrate or slip.  Cheaper FEPS will only have a foam tray, where the top of the springs meet directly with the Memory, Hybrid of Latex foam.  This is a cheap means of FEPS which over time will damage the Memory, Hybrid or Latex layer as these foams are not manufactured to withstand stress from springs.  You want to avoid these types of FEPS.

We have three FEPS models.  The Hybrid 6, Hybrid 7 and the Latex Fusion Zero Model.

A quality FEPS  unit will be entirely encased in a firm PU foam to ensure the springs don’t directly touch the expensive comfort layers of the mattress.

How do I compare FEPS?  The spring count is often used by manufacturers to claim their FEPS are better than others.  1500 pocket springs is better than 1000 isnt it?  Not necessarily.  It all depends on the size, gauge and style of spring used.  A mattress with more springs can in fact be softer or less stable than one with fewer pocket springs.  The bottom line is the number itself does not dictate the quality, you need much more information.

What FEPS do John Ryan Use?  We use 1000 pocket spring units in our Contemporary range.  This is based on a king size.  The springs are a medium tension, 3 turn barrel spring.  They are individually encased and then held in the FEPS foam box meaning they can’t migrate.  It also gives a consistent feel to the mattress.  We are members of the Institute of Spring Technology and have had our springs independently tested to confirm the tension and suitability of the springs for our mattress range.  For a  more detailed look at spring technology please see Johns excellent post here.

Octasprings and Springs-made-from-Foam – There has been a number of innovations in the last few years around FEPS and there is even a spring made from foam out on the market.  These mattresses have developed either springs or coils out of foam to be used instead of traditional pocket springs.

Many people often contact us and ask ‘What is an octaspring‘  followed by ‘Do you sell Octasprings?’.  Octasprings are probably the most commercially known of the foam springs and have been out for a few years.  Their advertising states they are cooler than solid memory foam as there are air gaps between the coils which helps reduce temperature.  Our view is that this maybe a clear benefit but given the price of Octasprings you maybe better off with a traditional pocket sprung FEP or traditional pocket sprung mattress if heat is an issue.  Memory foam will always be warmer than natural materials so even making springs out of foam does not remove their heat retentive nature.  The newness of these products also means there are no long term testimonials of the products shelf life or duration so it’s hard to comment on this.  We don’t use Octasprings as they are a proprietary foam spring used by Dormeo only in their mattresses.  Here at John Ryan Contemporary we are quite old fashioned that we only use tried and tested materials so we use high quality FEPs not foam springs.  The picture below is of the Dormeo Octaspring range they use in their mattresses, the different coloured foams indicate different tensions of foam spring.

Springs made from foam have been around long before Octasprings though and Kay Metzler, a UK based foam manufacturers.  Primarily these foam spring mattresses were marketed and sold in Germany and Europe.  They never really look off in the UK, probably due to the high cost and therefore retail price.  We have some of their early German prototype models which we have examined.  Different densities of foam can be used to create different tensions of foam springs which is quite interesting.  This has been the practice for traditional pocket springs since day one.  The castellated foam on top would be the comfort layer that covers the foam springs giving a softer top layer.

Here is a cutaway of the foam springs Kay Metzler developed with replacing traditional foam springs.

An example of how the foam springs react under pressure, these springs are then covered in a top layer of softer foam, as the comfort layer, the cutaway is there for demonstrative purposes only.

They are of a high quality but given the high cost we are not convinced they offer any benefit over and above a traditional pocket spring, more innovation than necessity.  Given that metal springs have been used for a century now for a huge range of uses, we are not sure why the use of foam now exceeds a high quality steel forged spring!  This again maybe subjective and its upto the consumer to decide whether the overall comfort of a foam spring is more suitable that a traditional pocket spring.