Advances in design, materials and insulation have made 2021’s crop of sleeping bags warmer and lighter than ever. Here's what to look for when buying your next sleeping bag.
There are two insulation types:
- Down: Water-resistant or hydrophobic down is now the norm and will resist clumping and dry more quickly (wet down clumps together and cannot loft). All down is compressible and lightweight, with goose down being of higher quality than duck down. Cheaper down bags will also use feathers in their insulation. The proportion of feathers to down is expressed as a percentage – e.g. 90/10 goose down, with the lower number representing feathers.
- Synthetic: Comprised of layered sheets of man-made fibres, these bags are cheaper and more durable than down-filled bags. They also insulate users even when wet. They tend to be bulkier and less compressible than down bags.
This is directly related to the warmth and weight of a sleeping bag. The higher the fill power (FP), the more air – and hence warmth – an ounce of down can trap. A high number also suggests the bag will be lighter because less down is needed to keep the user warm. It’ll also be more expensive because the down is of the highest quality.
Multi-baffled, anatomically-shaped hoods enclose the head and combine with neck baffles to minimise heat loss. A drawcord closure traps warmth.
Mummy-shaped bags have a smaller volume and are the warmest style, due to the reduction of ‘dead air’ space. Rectangular bags are more spacious and can be opened out like a blanket on warmer nights. A vaulted or '3D' footbox allows feet to rest in a natural upright position.
Three-quarter length zips reduce heat loss and weight. Two-way zips that run the length of the bag – or combine with a zip at the foot – allow for more ventilation options on hotter nights.
These contain down over key areas of the body, maximising loft and minimising air movement through the seams.
Pick a bag that best suits the majority of trips you’ll do. You can always increase the temperature rating by using a sleeping bag liner or by wearing insulated layers. Bags in this feature have all been tested to the temperature ratings standard EN13537 or ISO 23537-1 standard (for bags sold outside Europe).
The EN and ISO temperatures shown on the following pages are:
- Comfort: The temperature an adult woman could expect a comfortable night’s sleep.
- Limit: The temperature at which a standard man can sleep for eight hours in a curled position without waking.
- Extreme: The minimum temperature at which a standard woman can remain for six hours without risk of death from hypothermia (though frostbite is still possible).
The shell fabric is usually a ripstop nylon or polyester and will have a durable water repellent coating to repel water. Some bags use a fully waterproof fabric which will be more durable than those with DWR. The next-to-skin lining is usually soft-touch nylon or polyester. Linings help reduce clamminess by wicking body oils and moisture.
Because down insulation doesn’t trap air when it is compressed (i.e. when you’re lying on it) quilts do away with the bottom side of the bag, but retain a foot box which generally extends to mid-calf. So long as you have insulation beneath you (a hut mattress or sleeping pad), a quilt can offer similar warmth to sleeping bags but with reduced weight and pack-size.
Draught tubes prevent air passing into and out of the bag through the zipper.
Responsible Down Standard
All sleeping bags shown in this feature use certified Responsible Down Standard (RDS) down. The standard ensures:
- Any removal of down and feathers from live birds is prohibited
- Force-feeding of birds is prohibited
- Holistic respect for animal welfare of the birds from hatching to slaughter
- Each stage in the supply chain is audited by a third-party certification body
- Only products with 100 per cent certified down and feathers carry the RDS logo
Rab Mythic 600 $1499.95
Alpine bag with hydrophobic 900-fill power European goose down, down-stabilising chevron-shaped baffles, Pertex Quantum inner and outer fabric, three-quarter length two-way zip, down-filled neck baffle, angled footbox. Temp rating -5°C (comfort), -12°C (limit), -32°C (extreme) Fill weight 600g Weight 885g. www.outfitters.net.nz
Marmot Helium -9 $1199
Cold weather bag with water-resistant 800-fill power goose down, curved baffles, nautilus multi-baffle hood, snagless insulated draft tube, full-length two-way zipper, secondary ventilating zipper. Temp rating -5.2°C (comfort), -12°C (limit), -31.3°C (extreme) Fill weight 623g Weight 935g. www.marmotnz.co.nz
Rab Mythic Ultra 180 $1099.95
Warm temperature bag with 900+ fill power hydrophobic European goose down, 7D nylon outer and inner fabric, heat-reflecting titanium-coated inner, trapezoidal baffles, proportionally assigned differential cut, 3D draft
collar, draft tube, angled footbox. Temp rating 7°C (comfort), 0°C (limit), -12°C (extreme) Fill weight 180g Weight 400g. www.outfitters.net.nz
Rab Neutrino Pro 600 $999.95
Alpine bag with water-resistant Pertex Quantum Pro fabric, down stabilising chevron-shaped baffles, hydrophobic 800+ fill power European goose down, close-fitting internal collar, three-quarter length YKK anti-snag zip, draft tube. Temp rating -5°C (comfort), -12°C (limit), -32°C (extreme) Fill weight 600g Weight 1026g. www.outfitters.net.nz
Mont Brindabella XT 850 from $999.95
Four-season bag with 785-850-fill power water-resistant duck down, waterproof shell fabric, horizontal and vertical baffles with cross-block baffles to prevent down shift, down-filled draught tubes, full-length anti-snag YKK zippers, down-filled cordless collar, chest and hood drawcords. Three sizes. Temp rating -16°C (m), -10°C (w) Fill weight 850g Weight 1485g (m), 1455g (w). www.mont.com.au
Marmot Hydrogen -1 $999
Warm to cool weather bag with water-resistant 800-fill power goose down, curved baffles, nautilus multi-baffle hood, snagless insulated draft tube, full-length two-way zipper, secondary ventilating zipper. Temp rating 0.9°C (comfort), -4.8°C (limit), -21.9°C (extreme) Fill weight 309g Weight 665g. www.marmotnz.co.nz
Big Agnes Torchlight UL $799.99 (reg)
Cool-weather bag with expandable side panels for customisable fit,
850-fill power water-resistant DownTek, body-mapped baffle construction, jacket-style hood opening, insulated hood draft tube, vaulted footbox, zipper draft tube. Temp rating -2°C (comfort), -8°C (limit), -26°C (extreme) Fill weight 312g Weight 794g. www.gearshop.co.nz
Sierra Designs Nitro 0 $799
Mummy-shaped bag with 800-fill power water-resistant DriDown, 15D nylon ripstop fabric, patented self-sealing foot vent, draft-dodger collar, five-inch baffle spacing and side wall baffles, anti-snag zipper. Temp rating -9°C (comfort), -17°C (limit) Fill weight 736g Weight 1140g (m), 1110g (w). www.furtherfaster.co.nz
Mont Helium 450 Superlight from $749.95
A three to four-season bag with 800+ fill power water-resistant duck down, horizontal baffles, differential cut, down-filled draft tube, anti-snag zipper, contoured hood, full-length YKK side and foot zips, nylon shell and lining fabric. Three sizes. Temp rating -7°C (m), -1°C (w) Fill weight 450g Weight 800g (m), 770g (w). www.mont.com.au
The North Face Green Kazoo $750
Four-season mummy-shaped bag with 700-fill power water-resistant goose down, anti-compression pads and compression-optimised fill, fitted hood, vaulted footbox, zipper baffle, draft collar, sleeping pad loops. Temp rating -10℃ (comfort), -17℃ (limit), -39℃ (extreme) Fill weight 700g Weight 1500g. www.thenorthface.co.nz
Big Agnes Star Fire UL 30 $747.99
Three-season bag with 850-fill power water-resistant DownTek, body-mapped baffles, anti-snag draft tube, vertical sidewalls, contoured hood, anti-draft collar, ergonomic foot-box and one hand hood cinch, bluesign-certified. Temp rating 2°C (comfort), -4°C (limit), -20°C (extreme) Fill weight 343g Weight 652g. www.gearshop.co.nz
Big Agnes Sarvis SL 30 $699.99 (reg)
Three-season bag with 25cm adjustable length, internal built-in cinch system, sleeping mat sleeve, vaulted foot-box, anti-draft collar, internal stash pocket, 650-fill power water-resistant DownTek. Temp rating 1°C (comfort), -4°C (limit), -21°C (extreme) Fill weight 340g Weight 822g. www.gearshop.co.nz
Big Agnes Torchlight $699.99 (reg)
Cool-weather bag with expandable side panels to provide 30cm additional girth, 850-fill power water-resistant DownTek, body-mapped baffles, jacket-style hood, vaulted foot box, anti-snag draft tube. Temp rating 2°C (comfort), -4°C (limit), -21°C (extreme) Fill weight 397g Weight 1010g. www.gearshop.co.nz
Rab Summit 600 $699.95
Three-season bag with hydrophobic 650+ fill power European duck down, water-resistant Pertex Endurance shell, internal stash pocket, wide-angled footbox, three-quarter-length side zip, internal collar and hood drawcord, trapezoidal baffle chamber design. Temp rating -0.5°C (comfort), -6.5°C (limit), -23.5°C (extreme) Fill weight 600g Weight 1090g. www.outfitters.net.nz
Sea to Summit Spark SPII from $649.99
Technical lightweight bag with 850-fill power water-resistant goose down, zoned insulation, contoured mummy shape, half zip with two sliders, draft tube, hood draft collar. Temp rating 4°C (comfort), -2°C (limit), -18°C (extreme) Fill weight 300g Weight 490g. www.southernapproach.co.nz
Therm-a-Rest Questar 20°F / -6°C $669.99 (reg)
A three-season bag with zoned 650-fill hydrophobic down and a ThermaCapture lining to trap radiant body heat. Features mattress straps, quilt and blanket loops, foot warmer, oversized draft tube, snag-free zipper and external zip pocket. Temp rating 0°C (comfort), -6°C (limit), -23°C (extreme) Fill weight 540g Weight 991g. e.ampro.co.nz
Marmot Sawtooth -9 $599
Cold-weather bag with 650-fill power water-resistant duck down, wrap-around footbox, stretch tricot baffles, nautilus multi-baffle hood, full-length two-way zipper with draft tube, ventilating secondary zipper. Temp rating -6°C (comfort), -13°C (limit), -33°C (extreme) Fill weight 666g Weight 1130g. www.marmotnz.co.nz
The North Face Blue Kazoo $600
Three to four-season mummy-shaped bag with water-resistant 700-fill power goose down, anti-compression pads and compression-optimised fill, fitted hood, vaulted footbox, zipper baffle, draft collar, sleeping pad loops. Temp rating -3°C (comfort), -10°C (limit), -28°C (extreme) Fill weight N/A Weight 1050g. www.thenorthface.co.nz
Macpac Latitude XP Goose Down 500 $599.99
Four-season bag with 700-fill power 90/10 goose down, Pertex Quantum Pro shell, semi-rectangular shape, radial chest baffles, full-length side zip and foot zip, draft tube, inside essentials pocket, drawcord hood. Temp rating -2°C (comfort), -8°C (limit), -26°C (extreme) Fill weight 500g Weight 1119g. www.macpac.co.nz
Rab Women’s Ascent 500 $599.95
Mid-weight bag for first-time buyers, hydrophobic 650-fill power European duck down, Pertex Quantum fabric, wide mummy shape, proportionally assigned differential cut. Temp rating 0°C (comfort), -6°C (limit), -23.5°C (extreme) Fill weight 500g Weight 1025g. www.outfitters.net.nz
Sierra Designs Nitro 20 Quilt $549
Oversized quilt for more coverage, 800-fill power water-resistant DriDown, 15D nylon ripstop fabric, full-length insulated hand/arm pockets, hide-away hood. Temp rating 0°C (comfort), -6°C (limit) Fill weight 420g Weight 708g. www.furtherfaster.co.nz
Exped Lite +1 $499.99
A three-season bag with 800-fill power European goose down, soft-touch inner and outer fabrics, watertight construction, differential cut, full-length draft tube, anatomical 3D footbox and hood with drawcord. Temp rating 6°C (comfort), 1°C (limit), -15°C (extreme) Fill weight 290g Weight 780g. www.bivouac.co.nz
Marmot Never Winter $499
Warm-weather bag with recycled 650-fill power water-resistant duck down, wrap-around footbox, nautilus multi-baffle hood, down-filled collar, full-length YKK two way zipper, draft tube, stash pocket, ventilating secondary zipper. Temp rating 3.6°C (comfort), -1°C (limit), -17.8°C (extreme) Fill weight 370g Weight 850g. www.marmotnz.co.nz
Macpac Escapade Down 350 $429.99
A mild-weather bag with 600-fill power 80/20 duck down, water-resistant Pertex Quantum shell, trapezoid baffles with interlocking compartments, full-length side zip and foot zip, down collar with drawcord, draft tube. Temp rating 4°C (comfort), -2°C (limit), -18°C (extreme) Fill weight 350g Weight 996g. www.macpac.co.nz
Therm-a-Rest Space Cowboy 45°F / 7°C $299.99 (reg)
Summer bag with synthetic eraLoft water-resistant insulation. A ThermaCapture lining traps radiant body heat to help retain warmth. Three-quarter-length zip, mattress straps and hood drawcord. Temp rating 11°C (comfort), 7°C (limit), -6°C (extreme). Fill weight 270g Weight 545g. e.ampro.co.nz