APEX temperature rating

Discussion in 'Sleeping Bags & Quilts' started by Marco, Nov 27, 2019.

  1. Marco

    Marco Ultralighter

    Although comfort ratings for quilts are very subjective, I think it's worth to share the values we're currently working with:
    apex.png
    Our temperature ratings for quilts are roughly equivalent to the limit comfort temperatures (*) of the EN rating standard. That’s the temperature you commonly see as the EN rating of a sleeping bag. It’s defined as the temperature at which a standard man can sleep for 8 hours without waking.

    There is a real lack for women UL sleeping bags, not to say quilts. So we've been working for a while on this and have reached the previous values.

    How do you feel with these values? I have a special interest in women's feedback.

    (*) To make things clear, those are not EN temperature ratings. The EN standard (usually cited as EN 13537 but cancelled by EN 23537 since 2017) is designed to test traditional sleeping bags, not open quilts. As a consequence, the results of testing quilts are not really useful and the margin of confidence depends a lot on quilt design. This is the reason no quilt manufacturer provides real EN ratings. What’s worse, some quilt manufacturers provide temperature ratings that seems to be based on the EN standard, but that’s not really true (none of them provide lab certificates!). Even some sleeping bag manufacturers are not clear (honest?) in this regard. Take into account that testing a single bag has a cost over 2000 €.
  2. Foxster

    Foxster Ultralighter

    I take all sleeping bag and quilt ratings with a pinch of salt i.e. I simply don't believe them. Manufacturers often seem to pick their own numbers out of the air to improve sales.

    When buying a down bag or quilt it is far more useful to compare the amount of fill and it's fill-power. It gives a much more accurate comparison than some vague comfort rating.
    Diddi likes this.
  3. oreocereus

    oreocereus Section Hiker

    I ordered an apex 233quilt from you before you started officially stocking them. I haven’t pushed it to its extreme, but it’s definitely been below freezing and been fine (whereas I was often chilly even above freezing in my former apex200 quilt - but that quilt was a touch on the short side for my height and didn’t have a permanently closed foot box).

    I’d be curious to know how the expected ratings of apex degrade over time? I haven’t seen much good data on that yet. FWIW I’ve probably compressed and uncompressed that quilt 50-60x in the year or so I’ve have had it, and the most recent night was sub zero (didn’t have my watch with thermometer, but my water was frozen), so it seems to have held up well so far.
    Marco, FOX160 and Chiseller like this.
  4. cathyjc

    cathyjc Thru Hiker

    Woman here !! :D.

    I've never tried a quilt camping and I've used only down for the last 40yrs
    - but the way I estimate the warmth of a sleeping bag is by comparing the "loft" with that of a sleeping bag I already use. It gives me a "relative" performance estimate.

    I'm not sure how Apex would compare to down, inch : inch of loft - but their performance cannot be very different. Perhaps quoting loft, as the Americans do, might be informative.

    Style/construction etc. will be important as will the "skill" of the user - but the potential warmth will be reflected in the "loft". I think :cautious:.
  5. Foxster

    Foxster Ultralighter

    I have a feeling of deja vu here but...

    We already have a measure of loft of the filling for most decent bags/quilts: Fill power.

    It's the amount of space a specified weight of stuff will fill i.e. how fluffy or lofty it is.
  6. cathyjc

    cathyjc Thru Hiker

    NO - I don't care about how much fill of whatever quality - those can all be compromised by how the shell is constructed.

    Shells can vary in size and shape - tight versus capacious - thats always going to determine how the down is "spread around". Lots of good down in a wide/long bag is not going to be as effective as less down in a narrower/shorter bag.

    I know this from personal experience - a bag I had was not performing as expected (top notch bag and filling) - I tried to boost the loft but no amout of extra fill improved the loft as the baffles were too short (top to bottom) - the bag was just not built to loft more. Poor design IMHO.

    I've also had bags were there was insufficient down to fill "the void" and accumulated in cumps leaving cold spots - ie. ups and down in the depth of the "loft"of the bag.
    If you'd gone by the stats of the down in either bag you'd have been misled.

    I've learnt to measure the loft to estimate how warm I will be in what circumstances.

    Don't get me wrong I love lots of highest quality fill - but inches/cms loft tell me a lot more about how well the bag will insulate.

    I also assert that similar "loft" details will help in assessing the insulating potential of quilts.
    Effective quilt design is another matter.
    FOX160, Teepee and oreocereus like this.
  7. Teepee

    Teepee Thru Hiker

    I struggle with weight/area for synthetic. My brain knows well the performance of loft in a given temperature, for synthetic and down, for quilts and sleeping bags;coupled with the addition of reflective layers at various temps.

    Here's a graph to show loft/weight of Apex; https://backpackinglight.com/forums/topic/climashield-apex-actual-loft-thickness/
    ( I'm not Tom C)

    For me, as a warm sleeper, synthetic non reflective is roughly equal to down in terms of warmth/loft. Down insulation, for an average sleeper, gives comfortable warmth at the rate of 1"/ every 20 degrees F below 70F. I use 60F, and I find this works all the way down to under -40F.
    For a reference, I have a -40F comfort down bag that has 6.5" of loft, which is an accurate rating.
    A -30F Climashield bag with 5" of loft
    A -60F Climashield bag with around 8"
    A 10f Down quilt with 3.5" of loft.
    A 35F down quilt with 1.25" of loft




    Warmth of sleeping insulation is very subjective, especially with quilts. Just the type of lining has a massive impact of warmth. If it feels warm to the hand, it's always warmer to sleep in, no matter what clothes are being worn.

    Basically, what Cathy said. :D


    The curve ball in all of this is what a reflective layer adds. I've seen all the calculations that say it adds minimal warmth, and then I have thousands of nights using it and my anecdotal experience is very different to the sums.
    cathyjc likes this.
  8. dovidola

    dovidola Thru Hiker

    Lacking @cathyjc 's expert eye (not having bought many of these things) I have little option but to be guided by the temperature rating, plus a cautious pinch (perhaps 5C) of @Foxster 's salt.

    When it comes to temperature rating for quilts, I'd have thought it additionally problematic because the way in which a sleeper uses a quilt is inherently even more variable than the way a sleeping bag is used.
  9. oreocereus

    oreocereus Section Hiker

    Design also makes a big difference with quilts. Closed footboxes help keep the quilt wrapped around you (and well shaped footbkxes are more thermally efficient). Sufficient width or perhaps draft flaps (a la Ray jardines design) ensure no drafts if you’re a sleeper who moves around (many quilts use a strap system instead of being wide - arguments to be made either way). Being genuinely long enough to at least cover your chin without needing to pull it tight. Draft collars to seal the top could help. Etc etc. And of course there’s more “skill” to it perhaps - ie being savvy about wearing something on your head, developing the habit of making sure you’ve not pulled the quilt completely to one side when you roll over.
  10. cathyjc

    cathyjc Thru Hiker

    Agree re. The "skill" level of the user - probably why I've never tried a quilt - not sure I'd "get it right" and I've invested too much ££'s in sleeping bags - which brings me around to :-

    Yes, I've had a good few SB's over 5 decades.
    - I started with cheap synthetic bags my mother bought (-I was a child, she knew less than nothing and had very little funds).
    Thru' a variety of increasingly better options to some of "the best" items available.
    I've learnt a lot about what works for me. I sleep cold.
    What works for me won't be right for others - I cannot tell anyonw how much "loft" they will need at what temp. Unfortunately, you have to work it out for yourself.
    BUT I can say that saving in order to buy "the best" you can is well worth it and may save you a lot of wasted £'s and effort along the way.

    I find the only reliable way to compare 2 different products is to compare their loft. Other features may also be important - zips. hoods etc.

    Better quality down will get you the loft you need at less weight - that's the bonus.
    Foxster, edh and oreocereus like this.
  11. M@tty

    M@tty Hiker

    I have an Apex 200 sleeping bag and recently stepped out at between +1 and -2c for 5 nights wearing Brynje base layers and longs and want cold at least 8 hours uninterrupted sleep each night. Can’t comment on quilts though. But considering a Apex 167 Quilt to use alone in warmer seasons or with this bag when ultra cold.
  12. So I recently used the older Sestrals 200 out at around -3 and I felt quite warm, however with base layers and a fleece on. It’s interesting to note that you now say the 233 is good down to -4, but the old 200 was good to -5. Would you say the older ratings are now not accurate?
    Marco likes this.
  13. Marco

    Marco Ultralighter

    The old ratings were a bit optimistic for some people and (what's more important) were aimed to the UL community: they assumed you sleep with some insulated clothing. The new ratings are based on more customer feedback, and are more in line with the EN standard rating: they assume you sleep basically with a base layer.

    I think this a good move, because it offers more realistic values (the rating considers mostly the quilt, not your clothing / quilt system) and makes comparison with sleeping bags "easier".
    FOX160 and WilliamC like this.
  14. Marco

    Marco Ultralighter

    This is a good question, but hard to answer. It depends a lot on how much real use you put in your bag, and also how you compress it. APEX definitively has a much longer lifetime than other synthetics (e.g. Primaloft) but still not as long as down.

    Some customers and friends who are mountain guides (i.e. use their quilts a lot) told us that APEX retains a good amount of its loft after several years of use. On the other hand, I also have reports of quilts that lost their loft faster than expected. I suspect that over compression was a key factor in those cases. Also, you should take some care when stuffing an APEX quilt because it has no sewn through stabilization: push the quilt with your palm inside the stuff sack and take your time since fabrics are windproof.
    oreocereus likes this.
  15. Marco

    Marco Ultralighter

    These are the official specs of APEX:

    Captura de pantalla 2019-12-05 a las 11.54.05.png

    However, loft varies from batch to batch. In practice, small variations of loft doesn't affect insulation power too much, as far as fiber density (g/m2) is preserved. Fiber density can vary specially in APEX 67.

    Totally agree. This is why we are so happy with our schooler-ftc fabric. Nowadays there are a bunch of lighter fabrics, but all of them have a more "plastic", clammy touch to the skin which translates in less comfort.
    FOX160, Teepee and cathyjc like this.

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