Down insulation
Overview
Down insulation uses the fine plumage beneath the feathers of ducks or geese to trap air and provide warmth in jackets, sleeping bags, and quilts. It is known for high warmth-to-weight performance.
Key points
- Provides significant loft and warmth at relatively low weight.
- Performance is reduced when down becomes wet or saturated.
- Fill power and total fill weight both influence warmth.
- Ethical and sourcing standards vary by manufacturer.
- Requires some care in storage and use to preserve loft.
Details
Down insulation is valued in long-distance hiking gear for its ability to create a thick, warm layer of trapped air with comparatively little weight or bulk. Fine down clusters loft when uncompressed, forming a three-dimensional structure that slows heat loss from the body.
A common consideration with down is its sensitivity to moisture. When heavily wetted, down tends to clump, losing loft and insulating ability until dried. Many users therefore combine down with water-resistant fabrics, pack liners, or dry bags to keep critical insulation protected from rain, condensation, or leaks. Some products use treated down designed to be more moisture-resistant, though it is still handled with care.
Warmth is influenced by both fill power, which expresses how much volume a given mass of down occupies under standard conditions, and overall fill weight, which is the total amount of down in the item. Higher fill power can reduce weight for a given warmth level but may come at a higher cost.
Proper storage, such as keeping down items uncompressed when not in use, and periodic gentle cleaning according to manufacturer instructions, can help maintain loft over time.
Related topics
- cold-weather-layering-system
- down-fill-power
- gear-maintenance-storage-and-longevity
- shelters-sleep-systems
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