Sierra Design Revolutionizes Down Insulation

DriDown in Action, floating where normal down drowns.

We’ve always loved down. From jackets and vests to sleeping bags, those soft little feathers are the insulation elite for good reason. Warmth without weight, excellent breathability, and plush, comfy loft—except when down gets wet. Then it loses its capacity to keep you warm, and takes forever to dry.  Previous solutions to this problem mainly include wrapping down in various waterproof/breathable shell fabrics. But that adds extra weight, stiffer material, extra cost, and greatly reduced breathability.

That’s all changed now, thanks to Sierra Design’s new DriDown. Introduced in this summer’s sleeping bags, this new technique makes the actual feathers water-resistant.  And when they do get wet, they keep their loft and dry much faster than their less-enhanced relatives. This miracle cure occurs during the down finishing process (some time after it leaves the duck or goose and before it becomes insulation), when a molecular-level polymer is applied to each individual feather. This hydrophobic (water-hating) finish keeps the feathers dryer longer (manufacturer’s tests indicate five- to seven-times longer). The treated down maintains its loft in humid conditions (which can pancake non-treated feathers) and dries noticeably quicker when it does eventually get damp.  Sierra Designs will start unveiling the apparel with DriDown this August.

DownTek (made by Down Décor, a supplier of down since the 1990s) is also entering the game, supplying hydrophobic, quick-drying down to outdoor gear and apparel manufacturers including Big Agnes, LL Bean, Mountain Hardwear, and Brooks-Range, who will be rolling out their version of waterproof down in sleeping bags and apparel throughout this summer and the fall/winter seasons ahead. Which one works best? We’re testing now. Stay tuned.