Why Down? There are many alternatives for insulation materials used in quilts. They run the gamut from the various synthetic insulations to high fill power down. Each has its own merits and shortcomings. At JRB we began using down and continue to use down because as hikers we were looking for the lightest weight to warmth ratio alternative. The major drawback attributed to down has always been its susceptibility to moisture and its lack of insulating capability when wet. While the moisture can be a problem if appropriate precautions are not taken, it is not exclusive to down. We are of the opinion that if your quilt is wet it doesn’t matter whether it has synthetic insulation or down, a wet quilt is going to insulate less, and you will have a miserable night! The moisture issue relative to down is often overstated and perpetuated by the proponents of synthetic insulation. After all, how many times have you soaked your quilt in the woods. So, whether using synthetic or down, the best approach is to take the appropriate precautions to keep your quilt dry. An adequate tarp, a waterproof storage bag, and a healthy helping of common sense will prevent wet quilt problems.
The 800 Fill Power Down Sweet Spot. It has been our experience that 800 fill power down offers the most cost effective alternative in terms of down insulation. There is no such thing as pure down. All down is a mixture of feathers and down. 800 fill power and higher is more than 95% pure down, or less than 5% feathers. Fill power is a measure of the volume in cubic inches that one ounce of down will fill under a specified standard load (IDFL Standard). It takes 14% less 800 fill power down to fill a given volume than it does 700 fill power down. Similarly, it takes 12% less 900 fill power down to fill a given volume than is does 800 fill power down. As the fill power increases the cost of down increases fairly linearly up to around 800 fill power. However, above 800 fill power, down cost begins to skyrocket because of the limited supply, processing difficulty, and increased demand. There are a number of anecdotal reports that advocate 800 fill power down handles ambient moisture in field conditions better than higher fill power down because it is less fragile than higher fill power down. The bottom line is, in our opinion 800 fill power down is the “sweet spot” in both field performance and value.
JRB 900 Fill Power Philosophy. First of all, we have not redesigned the quilt shells. Whether the insulation is 800 fill power down or 900 fill power down the quilts are the same width and length. A three season model has a two inch baffle and a winter model has a three inch baffle. That means for a given quilt model, the internal volume is the same. The difference is that it requires less 900 fill power down by weight to fill that volume than it does 800 fill power down. Thus 900 fill power three season quilt will weigh about 1.5 ounces less than the same quilt with 800 fill power down. Similarly, a 900 fill power winter model will weigh about 2.25 ounces less than the same winter quilt with 800 fill power and a 900 fill power summer quilt will weigh about 0.75 ounces less than a summer quilt with 800 fill power down. The basic performance of the quilts is established by the quilt dimension/design not by the insulation material. We provide a 25-36% overstuff factor in all our quilts. This over stuff compensates for deviations from certified standards and it provides for field variations in humidity from laboratory rating and testing standards. It also reduces down shifting beyond normal expectations.
Again, the insulating performance of an 800 fill power quilt and a 900 fill power quilt of the same model are identical. The 900 fill power version is simply lighter.
Activ-dri Down™. Activ-dri down™ is a hydrophobic down treatment that keeps the down drier, while having no adverse effects on loft, fill power, or warmth retention. Third party testing has consistently shown that active-dri down™ stays dry 5 times longer than untreated down and dries 33 percent faster than untreated down. Activ-dri down™ is still down insulation and should be protected from direct exposure to moisture. All types of insulation, whether down or synthetic, will degrade in insulating capability when wet.