Fit, Part of the Feathered Friends Advantage
As is the case with jackets and pants, fit it is a critical component of sleeping bag performance. Bags with fixed girths –all of the ones tested in this comparative review and all of those found at a typical outdoor store—are limited by their inability to adapt to changes in clothing. For example, a bag that is thermally efficient when used without much clothing will likely be too small to allow a down jacket to loft properly. Through testing more than seventy sleeping bags we've found that fit is one of the most important attributes of selecting a sleeping bag. Fortunately, Feathered Friends offers four sleeping bags in their 20-degree line, of which the Hummingbird is the trimmest and lightest. This review applies both to the Hummingbird and to the other bags in the line; the amount of loft and the features in the various bags remains constant while shape changes. Therefore, regardless of your build and height we believe one of the bags in this line will work superbly for you.
Warmth is primarily determined by the amount of loft and the fit of a sleeping bag. As mentioned above, and covered in more detail below, one can choose from four different cuts of this bag to maximize thermal efficiency and comfort.
The Hummingbird has a conservative rating of 20 degrees Fahrenheit. Though manufacturers' temperature ratings often overestimate warm, we believe that Feathered Friends does the opposite, both with this bag and others. The Hummingbird lies closer to the average 15-degree bag we've tested.
The Hummingbird's 900-fill down and top-tier fabrics make it very warm for its 25.5 ounce weight. Many other traditional style sleeping bags are lighter, but they often save weight by reducing the amount of down (read: warmth) rather than eliminating features that might reduce weight without reducing warmth, such as is accomplished in the bags found in our Ultralight Sleeping Bag Review. In other words, if you want a solidly warm three-season bag with a hood and a full-length zipper it doesn't get any lighter than this.
Similarly, the Hummingbird's 900-fill down allows the bag to compress very small for its warmth. Sleeping bags that use lower fill power down need to add more down to achieve the same warmth as bags that use higher fill power down. For example, one ounce of 450-fill down occupies 450 cubic inches while one ounce of 900-fill down occupies twice that volume!! The Hummingbird uses less high-lofting down to keep you warm and allow the bag to compress small. Higher fill powers also have the advantage of being more durable than lower fill powers; there is less feather content and feathers tend to bend and break easier than the ultra tiny, super flexible clusters of the highest quality down. Also, down is many times more durable than synthetic insulation. With top-tier down, your money goes farther in many respects.
Comfort is a highly subjective topic that's argued about both by sleeping bag designers and testers. Some say that comfort comes from being able to move around within a sleeping bag while others believe that being able to move around with the sleeping bag is sufficient. We direct people that want to the ability to move within a sleeping bag to our camping sleeping bag review, where colossal rectangular bags provide heavenly, bed-like luxuries. For those of us that want sufficient comfort and weight savings at the same time, the Hummingbird provides an exceptional middle ground. Again, you can choose from four sizes. And, yes the Hummingbird is comfortable!! Its lightweight, high lofting design makes you feel like you're sleeping in a bubble of barely perceptible insulation. This is many times better than heavy, suffocating synthetic sleeping bags.
Due the relatively small amount of down found in three-season sleeping bags fabric plays a disproportionate role in influencing weight and compressibility. Top-tier ultralight downproof fabrics are advancing rapidly and Feathered Friends offers the Hummingbird in two fabric options.
"Nano" is a high quality fabric that bests the vast majority of others we've tested. "Pertex UL" saves additional weight and increases breathability without significantly reducing water resistance or strength. If saving weight is a top priority consider the UL option. Feathered Friends offers the UL fabric bundled with 900-fill down and the Nano fabric with 850+ down. If you want the absolute best, and have the cash for it, then go with the UL. Otherwise, the Nano and 850+ fill down combinations performs superbly— we've tested numerous Feathered Friends bags with both options. Bonus: there are several color options for each fabric. Choose from the colors available in stock or pay an extra $30 to have a bag made with your favorite color.
The Hummingbird's design is remarkably simple and effective. A passive draft collar helps to seal in warm air and a simple snap closure prevents the zipper from accidentally opening. There are no unnecessary bells and whistles to this bag—no zippered pockets, no pillow pockets, no pad attachment loops, or foot vents, or glow in the dark gizmos— the bag aims to provide as much warmth and comfort for the least amount of weight possible.
Feathered Friends fabric colors options. The Hummingbird is available in either Pertex Endurance UL (top) or Schoeller Nano (bottom).
As mentioned above, fixed girth bags are significantly less versatile than adjustable girth quilts. For this reason, we believe that quilts offer more performance people that primarily pursue multi-day overnight trips. The Hummingbird mitigates this limitation to some extent by using continuous horizontal baffle construction that allows you to shift down from the bottom of the bag to the top, and vice versa. Continuous baffles are excellent for three-season bags because you can move down to the bottom of the bag when it's warm out and to the top when it's cold out. Shifting nearly all of the down from the bottom to the top, and using a sleeping bad to insulate from the ground, makes the Hummingbird very toasty- perhaps equivalent to a 10-degree bag? This feature is a very important difference that separates the Hummingbird from the vast majority of bags currently sold by major outdoor stores like REI. Bags that trap down on the top and bottom in fixed baffles "waste" the down that gets compressed underneath you. And this is a common problem with all bags that feature Insotec Flow vertical baffles (Marmot Plasma 30, Sierra Designs Cloud, Nemo Nocturne, etc.)
The Marmot Plasma at left has a vertical baffles, a wide cut, and large toe box. The Feathered Friends Hummingbird at right has continuous horizontal baffles (more versatile) and is available in 4 cuts that maximize thermal efficiency and reduce weight.
Feathered Friends is a small Seattle-based outfit that has been producing top-quality down garments since 1972. After testing eight of their bags over the past three years, we are confident that they make the highest performance and most innovative down sleeping bags money can by. Although the Hummingbird is the highest scoring bag in our comparison, it is not without drawbacks. No sleeping bag is perfect.
The Hummingbird would benefit from a redesign of the hood. Bags like the Mountain Hardwear Phantom 0 and Marmot Plasma have hoods with small openings that are warmer and more comfortable than the Hummingbird's hood. We would prefer it if the Hummingbird had a smaller hood like the Phantom and Plasma. But this is a very small drawback that does not significantly influence performance.
Feathered Friends bags come with moderate quality stuff sacks that are not significantly water resistant, let alone watertight. We encourage you to consider upgrading to a better sack to protect your bag from water and adventure grime. See our The Best Sleeping Bag Stuff Sacks to compare our top picks.
Despite being exceptionally well designed and constructed, the Hummingbird costs less than some other three-season bags. This is a killer deal for a top quality bag. We believe it's worth every penny; the bag will keep you warm and comfortable for many years of adventuring.