Three Season Sleeping Bags

While it’s a convenient categorisation there’s no doubt that the traditional seasonal sleeping bag rating system (where sleeping bags are designated one, two, three, four or even five season) is highly subjective, and the introduction of the standardised EN13537  testing procedure was designed to make things a bit simpler for the consumer. Thanks to the variances in the way people sleep (a hot or cold sleeper, a side, back or front position, male or female, whether you’ve just eaten etc) I’m not convinced that it is. Nonetheless, put simply, the EN13537 Comfort rating is the lowest temperature that a woman can sleep for eight hours without waking up, the Lower Limit is the lowest temperature that a man can sleep comfortably, and the Extreme rating shows the minimum temperature that a woman can survive in for six hours. These test are conducted by the use of heated mannequins in a lab wearing a specific combination of clothing, and while they may not be 100% accurate, they offer a good basis for comparison between different models. Of course, being an EN rating this only applies to European manufacturers, but some US companies are adopting the ratings.

For convenience I’m going to assume that a three season sleeping bag – used in non-winter conditions  in the UK – should have a Comfort rating in the region of 0°C to -5°C. Through experience you’ll discover how you sleep in the outdoors, and whether you can get away with a slightly higher rated bag or need to carry a winter bag in the height of summer.

Then there’s the choice of a down or synthetic insulated bag. Down is expensive, but tends to last longer if looked after and offers greater warmth-to-weight and packability than synthetic insulation (though synthetics are catching up rapidly). Down becomes particularly useless if soaked, so there is a recent move towards down treated with a waterproof coating to help keep moisture at bay. Down fill power measures the ability of the down to loft or trap air, so bags with a higher fill power are more resilient to compression and will require less insulation by weight to provide the same level of warmth as lower quality down.

Helen and I will be looking at a variety of sleeping bags in this review and our physiologies couldn’t be more different (Helen is a petite female and I’m a large male) though sadly there are a relatively small number of woman-specific sleeping bags on the market.

Terra Nova Voyager 800RRP £340

Terra NovaA good no-frills down sleeping bag, Terra Nova only state the Comfort and Extreme temperature ratings for the Voyager range. Nonetheless, thanks to the 375g of good quality down packed into the bag, it should be suitable for most to just below freezing. The shell fabric is proprietery nylon and feels rugged where other brands make use of thinner branded fabrics like Pertex. But then Terra Nova know a thing or two about fabrics and the weight to durability ratio feels pretty good in this case. Most of the usual features are present including a thick zip baffle, but oddly there’s no neck baffle. I’m not sure if this is a weight-saving ommission or a means of reducing construction complexity, but I’d rather a neck baffle than the reflective strip that runs along the zip. Thankfully the hood drawcord can be cinched in tightly to make an effective seal, and while there is just the one length – 215cm – the fit is close enough to prevent excessive dead space. Oh, and a minor point – the minimalist stuff sack is a nightmare with cold fingers, it feels flimsy and was quickly discarded for a slightly bigger one at the expense of a few grams. It’s a lightweight and rugged option, but there are better options for the money.

Insulation: 800 fill power down Temp Rating: Comfort: 0°C, Extreme: -15°C Weight: 843g

Snugpak Chrysalis 3RRP £85

SnugpakFirstly – look at the price. A huge advantage of synthetic insulation is the ability to keep the price down, and in the case of the Chrysalis 3 from UK-based Snugpak you get a lot for this relatively modest outlay.  The bag is the classic mummy shape, with a water-resistant, breathable Paratex lining and shell, and enough Softie insulation to giving a Comfort rating of -5°C, which is ideal for UK non-winter use. Other features include a little LED light sewn into the hood which makes a nice reading light and is removable and the batteries replaceable. An expansion system – consisting of an additional zip and insulated panel – allows the bag girth to be easily varied, and a basic hook and loop arrangement enables the bottom of the bag to be folded back and secured. These measures ensure that smaller users aren’t trying to heat an excess of empty space within the bag, as well as making it ideal for growing children. These features soon add up though, and at 1600g it’s far from lightweight, and despite the compression sack doesn’t pack down particularly small. Regardless – at £85 for a -5°C rated bag with this level of features the Chrysalis 3 is extremely good value.

Insulation: Softie (synthetic) Temp rating: Comfort: -5°C, Extreme: -10°C Weight: 1600g

Mammut Sphere UL 3-Season RRP £360

MammutBy acquiring the Ajungilak brand Mammut have obtained access to a long heritage of insulation technology. The Sphere UL line represents a range of excellent minimalist down sleeping bags, of which the 3-Season model is an ideal do-it-all bag for the UK backpacker. There’s 500g of high quality goose down arranged within wave-shaped baffles which stops the down moving around inside the bag and causing cold spots. Both inner and outer fabric is thin but weather-resistant and breathable 20 denier ripstop nylon which resists down escape attempts as well as spilled tea. This is the snuggest sleeping bag reviewed – it’s hard to supplement the temperature rating with additional insulated clothing, and those that like to move around within the bag should look elsewhere. With this close fit in mind it’s important to select the correct length too – 180cm or 195cm. The hood has a thin brim which seems to offer increased protection while maintaining visibility and the three-quarter length zip flows freely and is easy to operate thanks to a simple cord zip pull. It’s backed by an insulated baffle, whereas the neck is sealed by a simple cordlock – combined with the snug fit and hood cinch the lack of insualted neck baffle isn’t a problem here. The weight is excellent given the quantity of down and temperature rating, and small packed size (in a sensible stuff sack) make this a great buy.

Insulation: 850 fill power goose down Temp Rating: Comfort: -1°C, Lower: -7°C, Extreme: -24°C Weight: 800g

Kelty Ignite DriDown 20 RRP £200

KeltyA £200 down bag is an excellent deal, made even better by the use of down treated with a hydrophobic coating which helps prevent the porridge effect that can occur when down gets soaked. In order to achieve this low price, cheaper and lower quality 600 fill power duck down has been used in preference to goose down and this fill, along with 30 and 50 denier fabrics –  adds some weight and bulk and has lead to a relatively high weight of just over 1300g. The hardware is practical and durable and there is both neck and zip baffles as well as a generous cut which permits movement within the bag without the bag feeling too loose. The temperature ratings feel fair and despite the lower-cost hardware and fabrics there isn’t any indication that corners have been cut – just a thoughtful approach to economical performance. The price and quality  is impressive and there can’t be a better hydrophobic down bag at this price, but the weight and bulk mean that there are better options for backpacking use.

Insulation: 600 fill power DriDown Temp Rating: Comfort: -2°C, Lower: -9°C Weight: 1320g

Rab Neutrino Endurance 600 Womens RRP: £350

rabThe only specific women’s bag tested, the cut is shorter in length and also wider at the hips than the men’s version, and was certainly a comfortable fit for me with plenty of wiggle room and space to sleep on your side. The outer is from Pertex Endurance which has good water resistance (and is therefore slightly less breathable), and the liner is soft (and thinner) Pertex Quantum fabric. With a fill weight of 600g it is pretty warm and I’d use it in all but the colder British conditions. The mummy shape is highly tapered but due to the angled foot box there still seemed to be plenty of room for the feet to shift about and lie comfortably without producing any cold spots. A baffle and anti-snag tape cover the 3/4 length YKK branded zip (left hand zip only on women’s version) and the hood has a collar baffle and drawcord. There is a useful internal zipped stow pocket. The bag is supplied with a quality waterproof compression sack (that does add 65g of weight) and also a large cotton storage bag. Relatively lightweight for the amount of insulation provided and a robust, comfortable bag that should last, justifying the higher price.

Insulation: 800 fill power down Temp Rating: Comfort: -7°C, Lower: -14°C, Extreme: -34°C Weight: 1120g

Therm-a-Rest Antares 20 RRP: £250

thermarestThis bag claims to reduce weight by cutting out down where it is not needed and relying on the insulation properties of the sleeping mat underneath your body. When I first unpacked the bag I was a bit skeptical, the outer fabric seemed thin and I wasn’t sure whether just having a panel of this between body and sleeping mat would be comfortable or warm.  The 405g of goose down is arranged with less at the side where Therm-a-Rest says studies show you are less likely to need it. This is not really noticeable to feel and there were  no cold spots when I tested it. The shell fabric is 30D ripstop nylon with a water repellent coating and normal 30D nylon lining the inside. A baffle covers the 3/4 length zip (left side only) and there is also a baffle at the neck and a well-fitting cord-adjustable hood. However the real innovation are the two lycra straps that hold the bag to the sleeping mat. I tried a variety of self-inflating mats of different makes as well as one from the Thermarest NeoAir range, all fitted well, and more-crucially did not slip or shift during the night. However given that you have to rely on the insulation of the mat, this bag really needs to be paired with a quality mat especially in colder temperatures. The shape of the bag allows you to sleep on your side or back and wriggling between positions caused no problem with the mat set up. There is an external stow pocket on side and the robust zip can be opened from both ends. It compresses really well into the supplied stuff sac (25g) and there is also a mesh bag for longer term storage. There is no specific women’s version, although it does come in two lengths, anyone over 6 foot will want to go for the long version. The temperature rating seemed fairly accurate – I’d definitely use this in most British summer/autumn conditions. It would have been nice to see an even greater weight saving to appeal to the keenest lightweight backpackers, however for the price this seems a good buy.

Insulation: 750 fill power down Temp Rating: Comfort 1°C, Lower -5°C, Extreme -22°C Weight: 890g

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