Articles by Danny Perez

Technology

The Great Insulation Debate: Down vs. Synthetic. Here’s What Really Keeps You Toasty.

Down and synthetic fill are used in cold weather and outdoor gear.Down insulation from duck and goose feathers is the warmest available insulator.Synthetic insulation is versatile and costs less, but isn’t as warm.Puffer jackets and parkas are a cold-weather must, but the insulation used in them is in more gear than you think. Down and synthetic insulation are the lofty materials packed into winter gloves, workwear jackets, and sleeping bags. You also see it in home goods like duvets and pillows. Both types of insulation work the same—they trap air next to your body, which is warmed by your body heat, keeping you warm. Genuine down insulation comes from duck and goose feathers, and is the warmest insulator you can get. Synthetic insulation has gotten a bad wrap, but proprietary technology from patented brands like 3M Thinsulate. PrimaLoft, CoreLoft, and Polartec, just to name a few, are still plenty warm and insulate when wet. So which is the best? Depends on what you prioritize.Down insulation’s weight should be considered when choosing outerwear for hiking, camping, or backpacking. Synthetic down is best for workwear when weight isn’t an issue, and it insulates when wet.Down is Lighter and WarmerOne may conclude that down is the best type based on that info, but it doesn’t tell the whole story. Down insulation from geese and ducks is warmer because the fibers are loftier and more efficient at trapping body heat. Down insulation is lighter than synthetic insulation, which is why it’s preferred by backpackers who need to keep their loads light on long treks. You’ll see “warmth-to-weight ratio” in product descriptions (and articles like these—I know I’ve used it before) to describe jackets that provide the most warmth without weighing you down—the majority of the time, they use down insulation. Down is known for its compressibility and packs down more compactly than synthetic insulation.Down insulation becomes useless when wet, as it loses its ability to trap air. It also doesn’t breathe, which can cause the wearer to overheat, especially during high-output activity like skiing or climbing. Luxury brands use down for this reason; the manufacturer isn’t expecting you to go snowboarding in a Moncler or Canada Goose parka.Fill Power and WeightWhen shopping for down, you'll see the fill power listed. Fill is the volume of an ounce of down when it's compressed. A decent jacket has 450- to 900-fill power, and the higher the number, the warmer the jacket. Make sure your down is ethically sourced and carries one of two sustainable down certifications: Responsible Down Standard (RDS) or Global Traceable Down Standard (Global TDS). RDS certification ensures down feathers are ethically sourced, and Global TDS provides transparency when tracking the source of down to ensure animal welfare.The fill weight is the amount of down in a piece of gear and should be considered as well. A jacket with a low fill power but higher weight can keep you as warm as one with a high fill power but very little of it. Synthetic insulation is sometimes listed only by weight, like in one of my favorite workwear jackets, Carhartt’s Yukon Extremes.Synthetic is Breathable and Water ResistantSynthetic insulation mimics down, but its fiber clusters are less dense. This means they don’t trap as much air, but they also breathe better. Carhartt uses synthetic insulation in its work jackets to prevent overheating, and Arc’teryx and The North Face do the same in their activewear jackets.Some product listings mention “mapping” to describe the insulation pattern in a jacket. This means they use down insulation in the body and synthetic under the arms or lower back for breathability. A significant plus of synthetic is its water resistance. Unlike down, synthetic insulation keeps you warm even when wet.