Prior to this review, I had never worked with NEMO Equipment. Founded in 2002, they’re a relatively young company and maybe that is some of the reason that I hadn’t previously taken any adventures with NEMO gear along. That said, I knew friends who loved their NEMO sleeping bags; when the opportunity arose to test the Kayu 15 Down Mummy Bag, I was seriously interested. All the specs were there: great down, thoughtful baffle design and some cool extra features promised a winner. I had some epic adventures in the Kayu 15, so it’s time to share how it went.

NEMO Equipment Kayu 15 Sleeping Bag Features:

  • 20D Nylon Ripstop and 30D Nylon Taffeta
  • Premium 800 FP down is ultra-packable, hydrophobic, PFC-free, and 100% Responsible Down Standard (RDS) Certified for traceability throughout the supply chain
  • Thermo Gills™ ventilation system
  • Waterproof and breathable footbox and hood protect against tent wall condensation
  • Full-length YKK zipper with snagless baffle construction and draft tube seals warm air in
  • Protected by the NEMO Lifetime Warranty
  • Weight: 1lb 14oz
  • MSRP: $389
NEMO Equipment Kayu 15 Sleeping Bag Review

The Kayu being versatile during a multi-day Deschutes float.

Go light (but bring a little comfort)

We’ll jump in with the basic specs of the bag. It’s built out of a 20D nylon ripstop shell, which is standard choice for sleeping bags due to the combination of ripstop properties and light weight. The inner lining is a 30D nylon taffeta, which was chosen because it has a slightly less plastic-y feel to it for next-to-skin comfort. It’s a good choice, as the bag felt noticeably less clammy to me than normal nylon linings. Finally, we’ve got a 40D nylon footbox; this is built with a monolayer waterproof technology that NEMO calls ‘Osmo,’ which is also used in their single-wall mountaineering tents. This wraps around the base of your feet and is ideal for the inevitable wet tent walls of multi-season Cascades mountaineering.

The bag weighs on at 1lb 14oz, which is pretty respectable for a 15 degree bag. A full 15oz of that weight is occupied by goose down filling, and that is a pretty solid amount of 800-fill down. There are more ultralight bags that could achieve a similar temperature rating with a smaller weight of 900-fill down, but those tend to get dramatically more expensive. The NEMO Kayu 15 holds its own with the best ‘mainstream’ bags (think Big Agnes, REI, The North Face, Sierra Designs) but could still be bested by certain niche, ultralight-specific brands like Feathered Friends or Western Mountaineering. I am very happy with this aspect of the Kayu 15.

NEMO Equipment Kayu 15 Sleeping Bag Review

This side-by-side shows the extent of insulation that opening the Thermo Gills can displace.

Other than the fabric, the Kayu 15’s foundation is its 800-fill, hydrophobic goose down. NEMO Equipment earns major brownie points in my book for emphasizing responsibly-sourced goose down. NEMO has also used their own hydrophobic treatment on the goose down. For conscientious consumers, NEMO Equipment stands out because all of their down is not only responsibly sourced but also PFC-free. That means that it is waterproofed in a way that is much less harmful to the environment than traditional methods.

I think it’s worth noting for consumers that this really does nothing to keep you dry; sometimes people buy these bags expecting them to be waterproof. That is not the case, and that technology is really only used in extreme cold-weather expedition bags. The purpose of a hydrophobic coating on goose down is to keep the down from absorbing as much of the water that makes it past the shell fabric, and therefore helps the down dry more quickly once it does get wet. For me, it’s a must-have if I’m going to take the bag on a Cascades climb when the forecast is iffy.

NEMO Equipment Kayu 15 Sleeping Bag Review

Take a look at the top of the zipper track, including a nice zipper garage.

So with that discussion, we’ve got most of the technical stuff out of the way. Now let’s move on to the actual experience of using the bag. The first thing that jumps out is the fit: this bag’s fit is totally dialed. For my 5’11”, 200-pound frame with somewhat larger shoulders and hips, I find the fit perfect. It’s snug, which some users find less comfortable but helps to eliminate cold air pockets. I also like the design of the hood – a critically important spot, since it’s where your face will be all night. It seals well and the shock cord toggles are easy to grab and release. One thing I’d fault NEMO for is the draft collar; it’s barely there, and personally I like a little more substance to a draft collar for comfort and flexibility. I’d offer the Big Agnes McAlpin SL5 as a better draft collar design.

I also found the little thermo-gill things weird but delightful. Do they work? I mean, logically, they must. You’re basically clearing away the insulation from two big patches right on top of your body’s core. I can’t say that opening them up was as immediately gratifying as sticking a leg out, but I think the idea is really more about fine-tuning the bag for comfort throughout the night. In that regard, yes, they work well. Also I’m impressed that NEMO managed to include two extra tiny zippers while still keeping the bag very light overall.

NEMO Equipment Kayu 15 Sleeping Bag Review

Testing conditions… in July.

Speaking of zippers, nothing particularly good or bad to say about the main zipper. There are better anti-snag designs out there, and there are worse ones too. I’d say NEMO opted on the side of a snaggier design to minimize adding weight to the bag; some of the least-snaggy designs add a decent amount of weight and bulk. There is improvement to be made here, and I’d point to the REI Co-Op Magna’s zipper as one better (and probably thoroughly patented) design. Fortunately, NEMO intends to change their zipper pull to a better model when they update the Kayu next cycle.

Finally, some thoughts based on actual use. I used this bag for some really unremarkable backpacking and camping, but it was also my trusted partner on a Cascades trip where the weather turned unseasonably foul for late July. To make matters worse, I was guiding this trip, so I had to keep getting in and out of the tent to do trivial things like checking on my party or making water. That meant a lot of moisture coming in and out of the tent. Normally I would never want to bring a down bag into a trip like this, but the weather really was worse than I expected.

To my sheer delight, the NEMO Equipment Kayu 15 totally stepped up; the hood and footbox’s waterproofing kept those two critical areas comfortable and dry, and even as the bag began to get a little damp it still insulated effectively during the freezing nighttime temperatures thanks to the treated down’s enhanced loft.

The Good

  • Lots of features at a pleasantly light weight
  • Top-notch fabric choice, with three different specific fabrics
  • The choice of responsibly-sourced down and Nikwax waterproofing is optimal
  • I really liked the ‘Thermo Gills’
  • Excellent fit to minimize dead air and insulation without impacting comfort unduly

The Bad

  • Draft collar could be plumped up for comfort
  • Zipper track could also be improved

The Bottom Line: Nemo Kayu 15

I’m sold on NEMO Equipment. Their Kayu 15 ultralight sleeping bag is really a great product, and I’m scratching my head as to why I waited so long to use their gear. What impresses me about the Kayu is that it manages to cram some extra-clutch features (like the funky vents, but also waterproofed areas) without becoming heavy. The high fill-to-weight ratio is also solid. In short, it’s one of those rare products that manages to be suited to true fast-and-light alpinism with a featureset that will baffle your ultralight buddies who have chosen to share a toothbrush to save weight. It’s a great bag.

Buy it now: Available at

About Author

Kevin Glover is an outdoorsman living, climbing and biking in Spokane, WA. Originally from the Nevada high desert, he moved to the PNW for its mild winters and allergen-free summers. He has guided throughout the Cascades and Enchantments for Peak 7 Adventures.

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