What is the FILL POWER of a down duvet?


‘FILL POWER’ is a standard measurement which tells us the quality of the down filling of a duvet. We imagine you have seen a wide range of duvets and have asked yourself why their prices vary so much. Well, the simple answer is that not all kinds of filling are the same, but it depends on where the down comes from, its heat-retaining capacity, softness, weight and comfort.


The quality of down depends on where the down comes from.

Although you can find on the market duvets filled with either duck or goose down, without any doubt at all, the best are those filled with goose down.  Moreover, whilst it is of great interest to know that the older the goose the better the quality of the down, it is also important to know in which part of the world the geese have been reared. This is because the colder the region the softer the down; indeed the down from geese reared in northern Europe is the most sought-after.

The ‘fill power’ (FP) of a down helps you to differentiate between duvets, to know whether or not you are buying a good quality product and if the price is reasonable. When deciding to purchase a down duvet your aim should be to acquire a duvet which is efficient, light and comfortable with an adequate level of insulation capacity. The more volume the down has with which to trap air, the better the duvet.  Air, after all, is one of the best thermal and natural insulators.


But really, what is Fill Power (FP)?

Fill Power (FP) shows us the overall efficiency of a down duvet including its capacity to insulate well.  This efficiency is measured using a scale of 1 to 10 (in Europe) or 100 to 1000 (in UK and US) depending on where you purchase the duvet. The higher the reading on the scale, the better the down is. As an example, a duvet with an FP reading of 600 (or 6 in Europe) is lower in quality than a duvet with an FP reading of 800 (or 8 in Europe), the latter possessing 33% more fluffiness, shape retention capacity and greater insulating power. The duvets with the best Fill Power (FP) are of course those of 900 or 1000 on the FP scale. These duvets are the best of the best and, needless to say, they are more expensive and have higher insulating properties and are more comfortable.  They are well worth the extra investment!  The higher quality reflected by the FP will mean you are buying a duvet which is longer-lasting, is softer, and will retain its original shape and fluffiness far longer.

It isn’t difficult, of course, to find cheap down duvets on the market too!  Be careful! They can be found easily in the larger shopping centres and big department stores, but very often you will find very little information is given regarding the filling. In many cases these duvets are filled with down which comes from Asia, are of lower quality, cheaper, and don’t last as long. We suggest you don’t trust the efficiency of these duvets unless the sales assistants are able to give you detailed information about the filling power of each one. Always insist on receiving clear and detailed information before buying!


How is the FP measured?

In technical terms the FP measurement is the volume or space occupied by 28.35 grammes (One ounce) of down under normal or standard conditions. Depending where it comes from, its quality, and its physical characteristics, one down will occupy less or more volume; a good quality down will be fluffier and more voluminous due to its ability to trap more air within it. It is because of this that the same weight of down with an FP of 800 (8 in Europe) will occupy more volume than a duvet with and an FP of 600. It will have a better insulation capacity, will be softer and lighter and consequently much more comfortable.


 Can you easily appreciate the difference between a good down and a poorer quality one?

Yes, it is simple to recognize the difference! Down is made up of tiny and exceptionally fine filaments, all of them having a central nucleus or centre. The longer and the more abundant these filaments are, the better the quality of the down in question; insulation will be better and so too will its FP coefficient. The life of the duvet will be longer, it will retain its original shape and at the same time it will be fluffier, lighter and more comfortable.

If you require any further information about the fill power of a duvet, do not hesitate to contact us. It will be our pleasure to help you.

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