R Rating on Sleeping Mats confused.com

[pistonbroke]

I sort of understand how the R rating on insulated sleeping mats is achieved by using different types and quantities of filling but can't get my head around how the numbers on lightweight non-filled mats are calculated. I can't work out the claims that the more expensive types costing €120-150 can be better than budget models. I recently bought a waffle type mat for under €20 which seems pretty well made with a non return inflation valve and easy deflation. It looks remarkably similar to ones costing 3 of 4 times as much, what's the catch? Are R ratings of under 4 or 5 just marketing bs?

[whitestone]

The cheap €20 mats are basically old fashioned LiLos, they have zero insulation in them, they'll provide padding but no warmth. In summer you won't notice much difference between mats with varying R-values but in cooler temperatures and especially when the ground is frozen or close to freezing then the cheap mats with low R-values will soon become uncomfortable. With no insulating filling the air in the mat will form convection currents transporting your heat to the ground.

The R-value is the reciprocal of conductivity so the manufacturer will work out how much heat is conducted from one side of the mat to the other and find the reciprocal. Conveniently R-values are additive so if you take a mat with an R-value of 1 and one with an R-value of 2 then you've got the equivalent insulation of a mat with an R-value of 3. Also if you've two identically constructed mats then the thicker one will be warmer by whatever ratio between the two mats, so twice as thick = twice as insulating.

Note that there are two R-values: the American one which uses a larger value range of 1 upwards and the ISO value which tends to be in the 0.1 to 0.5 range.

[Bearbonesnorm]

Many cheap uninsulated mats claim to have an R rating higher than what it probably is. However, it could be that the construction of some may limit the free movement of air to a degree which might raise the value slightly.

I believe the US system is generally easier to understand and compare, as I can certainly relate better to 3.5 than I can to .32

[pistonbroke]

Having seen a couple of videos where various mats are cut up to reveal their construction, I suppose my question is does adding a layer of what looks like a metallised film such as mylar as the filling in the sandwich of LDPE really double or triple the insulating properties. Comparing the cheaper types to a lilo feels similar to saying a cooking pot is just a baked bean can. I suppose I'm just struggling to work out how a Thermorest neoair can justify being 6 times higher in price to the one I've just bought or why even branded ones that don't have the foil layer are 2 or 3 times the price?

[whitestone]

There's a whole host of factors in "the price" whatever you buy, whether that's R&D, cost of materials, cost of production, paying lawyers to protect patents and IP, safety testing, etc. Then there's the simple fact that any company will charge what they feel they can get away with and maximise profits - if you could sell 10,000 items at €10 or 1000 of the same item at €100 which do you do? The answer is the latter as you can always drop the price a bit to create a "bargain" and still give yourself lots of profit, you've no wriggle room with the former.

At the customer end there's perceived value which is a whole different kettle of fish (useless as an insulating layer )

As to the claims that a mat has a specific R-value, manufacturers aren't going to be wildly out so if they quote an R-value of 3 then it's going to be somewhere between 2.9 & 3.1 rather than 1 or 2. It's an easily testable figure in the lab so they'd be opening themselves up to lawsuits and malpractice if they made misleading claims.

[Bearbonesnorm]

As to the claims that a mat has a specific R-value, manufacturers aren't going to be wildly out so if they quote an R-value of 3 then it's going to be somewhere between 2.9 & 3.1 rather than 1 or 2. It's an easily testable figure in the lab so they'd be opening themselves up to lawsuits and malpractice if they made misleading claims.

This is only true if you're assuming something is being made / sold by a reputable company. My experience is that some of the Chinese companies simply take the 'tell the custmomer what they want to hear' approach.

Neoair and Exped are market leaders and innovators and market their products as 'premium'. Whether paying a premium for their products represents ecomomical sense is entirely up to the individual.

[dlovett]

I figured that my x-therm was the same cost as on night in a modest hotel. It has now given me many nights of good sleep, so value for money it works for me. On my previous cheaper mats I never slept as well. When you only have a few hours to sleep, getting some good sleep is important if you are going to carry on straight afterwards.

[Mariner]

The higher the R-value, the warmer the pad will be. In general, sleeping pads with R-values of 0-2 will only be good for warm weather trips. R-values of 2-4 are good for most 3-season backpacking conditions. R-values of 4-6 are good when the temperature drops around or below freezing.

Just found this statement on a website.
When I bought my Synmat I found out later that they do a winter version.
If I used a winter rating mat all year round would I be too hot at some point in the year?
Something I have yet to experience.
If not apart from a price/weight increase why bother making an R3.n and an R5.n?
Does the R factor matter more to quilters than baggers?

[ScotRoutes]

The higher the R-value, the warmer the pad will be. In general, sleeping pads with R-values of 0-2 will only be good for warm weather trips. R-values of 2-4 are good for most 3-season backpacking conditions. R-values of 4-6 are good when the temperature drops around or below freezing.

Just found this statement on a website.
When I bought my Synmat I found out later that they do a winter version.
If I used a winter rating mat all year round would I be too hot at some point in the year?
Something I have yet to experience.
If not apart from a price/weight increase why bother making an R3.n and an R5.n?
Does the R factor matter more to quilters than baggers?

Price/weight (pack size) are the only downsides as far as I can see.
If I wasn't using a quilt then I'd also be considering a Klymit X Frame (at least for summer use).

[RIP]

"they do a winter version. If I used a winter rating mat all year round would I be too hot at some point in the year?"

FWIW, I have UL7, HL and Winterlite ("winter version"). I often now use the WL all year round cos it's only 40g heavier than the HL and I don't get too hot at any time, but mainly cos I can't be arsed to keep swapping round... (it's my choice of s'bag which makes me too hot or not..)

[Bearbonesnorm]

Unlike a sleeping bag, I'm really not sure that a mat can 'be too warm' ... although they can be waaaayy too cold

[Lazarus]

Only way to get way to warm is a winterone in the middle of summer

anyway back to the OP

I suppose my question is does adding a layer of what looks like a metallised film such as mylar as the filling in the sandwich of LDPE really double or triple the insulating properties

From experience YES

Having just returned from three days on my old multimat - gave the eldest child the Thermarest crinkly as that is what parents do- then i can say for certain the the layer in a does indeed provide much more warmth than nothing at all which is what the multimat has. It was noticeably colder - TBH I think I would have taken another bag instead of my usual summer bag - this thought has never entred my head with the thermarest which i will be using with the same bag in sept and possibly October

If I used a winter rating mat all year round would I be too hot at some point in the year?

well my[ other/ youngest] son survived at 16 degrees sleeping on my proper winter one [sea2summit R=5.7 iirc] and complained it was cold so I am going for a NO there but have never personally slept on it myself in summer.

[Alpinum]

Unlike a sleeping bag, I'm really not sure that a mat can 'be too warm' ... although they can be waaaayy too cold

I had a few nights out in just above freezing
on a stupidly warm downmat and found I can go with the thinner quilt as it pushes my feeling for warmth just a few degrees lower. A quilt I usually go cold below 5 °C was quite okay at 2 °C.

If I wasn't using a quilt then I'd also be considering a Klymit X Frame (at least for summer use).

I use the short version for short trips (up to a week) and 2 - 3 season use only with quilts. Works well for me in relatively warm weather.

Once I use sleeping bags it's well and mostly below freezing and then I go for a mat free of holes.

[Bearbonesnorm]

I had a few nights out in just above freezing
on a stupidly warm downmat and found I can go with the thinner quilt as it pushes my feeling for warmth just a few degrees lower. A quilt I usually go cold below 5 °C was quite okay at 2 °C.

No doubt Gian but I still don't think you can have a mat that feels too warm.

[Alpinum]

No doubt Gian but I still don't think you can have a mat that feels too warm.

Oh yeah, I definately agree with you.
I sleep warm and quickly feel sticky with a too warm quilt/sleeping bag. Using what would be a 'too warm' mat, I just sleep really well.

I was just kind of trying to make the point, that a warm mat will have an effect on how warm your quilt/sleeping bag will be and on the importance of regarding the mat as a part of your sleeping system you can play with - adjust to your needs.

[ScotRoutes]

If I wasn't using a quilt then I'd also be considering a Klymit X Frame (at least for summer use).

I use the short version for short trips (up to a week) and 2 - 3 season use only with quilts. Works well for me in relatively warm weather.

Once I use sleeping bags it's well and mostly below freezing and then I go for a mat free of holes.

Interesting. I assumed that the "holes" would feel quite cold without the added layer of sleeping bag beneath you.

[Alpinum]

If I wasn't using a quilt then I'd also be considering a Klymit X Frame (at least for summer use).

I use the short version for short trips (up to a week) and 2 - 3 season use only with quilts. Works well for me in relatively warm weather.

Once I use sleeping bags it's well and mostly below freezing and then I go for a mat free of holes.

Interesting. I assumed that the "holes" would feel quite cold without the added layer of sleeping bag beneath you.

It's definately the least warmest mat I have, I feel the Z-Rest to be warmer for example and the short version X-Lite definately is warmer too, yet for summer use in the Alps or HT550 etc. I feel I get enough from the Klymit.

With the Klymit I take a bit more care in choosing the right spot. Soft, grassy or when below the tree line with loads of needles etc.


From some summer trips in the Alps...


This photo was taken during a morning with -5 °C - round about the comfort temperature of the quilt and I was tired and a bit hungry - yet slept really well and even had a little lie in. Thanks to comfy grass

[whitestone]

I'm with you on the Klymit Gian.

Even though it's really meant for use with a sleeping bag to fill up the holes I've found that during the months where the ground's warmer it's fine with a quilt especially on "softer" ground.