Top Quilts and Goose Down Insulation
What is a top quilt? Well, generally speaking, a top quilt is exactly what it sounds like… a sleeping bag without a hood or backside. Deviating from a tried and true traditional design like a sleeping bag might seem counter intuitive to staying warm on those cold nights in the back country, but there is sound logic behind this evolution.
To better understand why a quilt makes sense, you must first understand how goose down insulation keeps us warm. Each ounce of premium quality down has millions of tiny filaments that interlock and overlap to create a protective layer of static air that is greatly inhibits the movement of heat. It is not the down fibers themselves, but the tiny pockets of air being trapped by the down that actually do the insulating. The more mature the goose down, the larger the clusters will be and the greater number of air pockets available for more efficient insulating. These larger clusters greatly improve loft, which is a key factor when determining insulating power. Because of its resilience of down insulation, you can scrunch it up or flatten it out, and all it takes is a good shake for it to fluff up and bounce back.
Premium goose down is approximately three times warmer per ounce than most synthetic insulation. Far less down is needed by weight than other insulation, which means a much lighter, more compact, and warmer product. Depending on use, synthetic insulation will sometimes begin to break down and separate over time. This can leave cold spots and a lesser temperature rating than when the bag was new. Conversely, goose down is known to continually reloft after many years of use. It also does a great job of conforming to the shape of the user. Goose down also has the ability to breathe, and to an extent, wick away perspiration.
So, using this understanding of down insulation, you might be beginning to understand why a quilt-style sleep system can work just was well, and sometimes better, than a traditional style sleeping bag. When you are lying in a sleeping bag, the weight of your body is greatly compressing whatever insulation is directly underneath you. This means virtually no loft. No loft means no warm pockets of air…which translates into a long night of shivering…Since the portion of the traditional sleeping bag that is underneath is just being compressed and is not really keeping you warm, why should it take up valuable space in your backpack? Answer: it shouldn’t. Another benefit of a top quilt to a hammock camper is that you can generally get by with a narrower model.
And so, the quilt was conceived.
Hammock camping has really embraced the concept of the top quilt. It is much easier to get into and out of a Top Quilt when sleeping in a hammock. This is especially useful during those occasional late night trips to the privy :)