That said of course an ultralight 800 fill power jacket may not be as warm as a 700 fill power jacket that contains more down.
Marmot 700 fill down jacket temperature rating.
650 700 fill power is sometimes used in high contact zones of some active garments.
Higher quality down that has even larger clusters more loft and great insulation with low weight.
Because unlike fill power parameter in down jackets there isn t a common denominator to compare different types of synthetic insulators in an analytical way.
Although the temperature rating system has its flaws there are still other numbers figures and facts to consider when looking for a great down jacket.
Comparing the temperature ratings of synthetic insulated jackets is more difficult.
Luxury down comforters will often have a fill power rating of 700 or above.
A jacket with 500 fill power and 10 oz.
Of down will be warmer than a 800 fill power jacket with 5 oz.
A 900 fill power down jacket that has only 30g of down fill won t be warmer than a 450 fill power jacket with 100g of down fill.
Its zippered handwarmer pockets and elastic bound cuffs and hem help to seal out cold air and maintain a secure fit while you re in motion.
It would also compress to about half the space.
Clo value is the insulation power of an insulation setting.
Slightly lower fill power down i e.
Very few jacket makers report fill weights though.
Like most of the parkas in our collection it features 700 fill power and 13 ounces of white goose down.
Similarly while synthetic insulation traditionally was not as lightweight compressible and durable as down the best modern synthetics including those reviewed below have a warmth to weight ratio and compressibility that compares with mid grade 700 fill.
Maybe except one parameter.
An 800 fill power jacket will require less down than a 500 fill power jacket to provide the same warmth.
With 700 fill power with down defender this packable down jacket keeps its wearer warm and comfy in chilly damp environments.
In theory 50g of 900 fill power down would be the same warmth as 100g of 450 fill power down.
With the down weight and down to feather ratio being equal an 800 fill power jacket will be warmer than a 500 fill power jacket.
