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Down Fill Power; Which one should you choose?

Down Fill Power

There are all sorts of options out there when choosing a down jacket, such as the insulation type, the style and the Down Fill Power, not to mention the colour! There are advantages and disadvantages to both down and synthetic insulation, but if you’ve decided that down is for you, there are several different Down Fill Power grades to get familiar with and choose from.

Down jackets tend to use either goose or duck plumage, which are both known for their exceptional warmth, but when it comes to Down Fill Power, what does this mean and which one is right for you?

What is down?

Down can be found in between the birds’ skin and their outer, waterproof feathers. The down is exactly what geese and ducks use to keep them warm and to help them to float on the water, and is unmatched in its ability to insulate. This is because air is one of the best insulators out there, and down clusters capture air within them. So with a down jacket on, air is warmed by your own body heat, and then trapped next to you within the down, which is why you’re kept so warm.

The one thing to bear in mind when on the quest for a down jacket is that the down does in fact come from an animal, so it’s important to make sure that whichever Down Fill Power you choose, make sure the down is certified by the Responsible Down Standard.

Down Fill Power

What does Down Fill Power mean?

Down Fill Power is the rating system used to assess the quality of goose and duck down. Ranging from 300 – 900+, the number can usually be found on the sleeve, tag or label on the item. The number is representative of the volume in cubic inches of a single ounce of down when the down is fully lofted, so essentially, Down Fill Power is how much space an ounce of the down takes up.

The higher the number of the Down Fill Power, the more space one ounce takes up, resulting in more air being trapped and the jacket being warmer. However, this doesn’t always mean that the higher the Down Fill Power, the warmer the jacket; that depends on the weight and quantity of down.

For example, a jacket with a low amount of 800 Down Fill Power may not be as warm as a jacket with a high amount of 500 Down Fill Power, but the warmer jacket will weigh a lot more, making it unsuitable for some activities such as hiking, climbing or skiing. The lower fill power will also be a lot less compressible as there’s less air in the down to squash.

Down is formed in clusters, and the maximum loft is achieved when the down clusters are fully expanded, as this is when they take up the most space. Larger clusters come from older birds, and because they are larger, they can trap more air, giving them greater insulating power. So higher the Down Fill Power, the larger the clusters tend to be, and the longer the jacket will retain its loft.

High quality down is considered to have at least 550 Down Fill Power. There’s no equivalent test for synthetic insulation, so you can’t use the Down Fill Power rating system for those kinds of jackets, making it difficult to compare the two in terms of warmth to weight ratio.

Synthetic Insulation vs Down Fill

Synthetic Insulation and Down Fill each have their own advantages. A synthetic jacket is better in wet weather but doesn’t always keep you as warm, whereas a down jacket is arguably the best material to keep warm, but won’t perform too well in the rain. Here at Dark Peak, we offer both synthetic and down NESSH jackets, so you can choose the one that fits your lifestyle best. Our synthetic jackets are both vegan and allergy-friendly, sporting 3M Featherless FL700 insulation; a synthetic insulation that gives industry-leading warmth to weight as well as incredible compressibility. Our down jackets use 850 Down Fill Power goose down, putting it right at the top end of the scale in down quality. What’s more, we only ever use Responsibly Sourced goose down, making for an ethical jacket, as well as an incredibly warm and lightweight one.

Down Fill Power

Which one should you choose?

A high Down Fill Power jacket will be lighter and more compressible than a lower Down Fill Power jacket of the same warmth, so if you’re after a down jacket to keep you warm whilst you’re out hiking or climbing, a high Down Fill Power is right for you.

The right Down Fill Power for you depends on the main activity you’ll be using your jacket for, and how warm and compressible you need it to be. If you’re a keen hiker or climber, high Down Fill Power is the right choice for you, and our NESSH Jacket boasts a very high 850 Down Fill Power, which will keep you toasty warm when you’re out in the elements. Take a look at our product page to find out more about our high quality, high Down Fill Power NESSH Jacket.