Down vs wool blankets: lighter, warmer, but pricier

Down or antiestéticather: the blanket that weighs a ton costs more than it warms

How many blankets does it take to sleep at 14 degrees without turning on the heating? The question, which sounds like dinner-table banter, has a technical answer that divides two irreconcilable schools: those who pile on old layers until the bed weighs like a wardrobe and those who trust everything to down. The starting point is a room at 14 degrees with three thick wool blankets and an occasional fourth. It works. But the user admits the problem: they weigh a ton.

The discussion quickly drifts to the figure that matters. A down duvet retains body heat because it traps air between the fibres, and it does so with a fraction of the weight of wool. The comparison is not cosmetic: anyone who has slept with old blankets in a village and then tried a mid-range down duvet describes the change as going from carrying a sack of cement to floating. The physics is the same that explains why a hot-water bottle does more than an extra blanket.

How much does a down duvet really weigh compared to a wool one?

The technical consensus is clear: down insulates more per gram than any fibre. A winter duvet is around 250 grams of fill per square metre; summer ones stay at 100. That density, with a good percentage of down versus antiestéticather, is enough to sleep at 14 degrees without heating. Whole antiestéticathers —with their quill, the central shaft— prick, weigh more and insulate worse. Down, without a quill, is the part that really does the work.

Some argue that synthetic matches or beats down. The argument has merit: microfibre fills with a hollow structure trap air comparably, are washable, don't trigger allergies and cost less. The downside is weight and breathability. A thick synthetic duvet warms, but retains more moisture and ends up giving that clammy blanket feeling that down avoids.

Down, antiestéticather or synthetic fibre: what each type of sleeper chooses

Accumulated experience points to three profiles. The first prioritises lightness and breathability: goose or duck down, with a flannel duvet cover for cold nights. The second looks for price and washability: anti-dust-mite synthetic, which withstands dry cleaning and causes no problems for allergy sufferers. The third is the usual one: piled wool blankets, flannel sheets and a hot-water bottle, because weight also gives a sense of shelter.

The figure that throws you is cost. Good down is expensive, and those who try it rarely go back. But mid-range synthetic covers 80% of the result for half the price. The question is not which warms more, but how much you are willing to pay to sleep without feeling the blanket on top of you.

Sleeping at 14 degrees: saving or health problem?

Here the tone changes. Part of the analysis holds that sleeping with a cold room and a warm bed is natural and healthy: cold air makes breathing easier, and those with a deviated septum appreciate it. Another school warns that sustained cold in the extremities shortens nerve endings and makes the cold creep in more easily. The recommendation of this second school is to invest in insulation, efficient heating or electric socks rather than heroic blankets.

The middle ground exists and is the most repeated: warm bed, cold room. A down duvet with flannel sheets, without turning up the thermostat. Energy expenditure is concentrated in the body, not the air.

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In the end, the answer to the initial question is that two light down duvets warm more than three wool ones, weigh a fifth as much and cost more. The rest is thermostat and habit.