Question about sleeping bag insulation hammock vs ground

[dakotaross]

This makes sense, so then why are full blown sleeping bags so prolific?

Real good question. I googled the history and got some, but there is notably no mention of the bottom insulation issue - except on Wikipedia and it looks like a modern day reference. With animal skins being the first materials used in the "bag" design, my guess is that they offered a barrier between body and earth (dirt, snow, etc.) and that the skins necessitated a shape that was not conducive to the standard rectangular blanket used on a regular bed. There would be no excess to "tuck" like we commonly do now with quilts on the ground, so it was sewn to keep out drafts. My guess is that from there, the bag design became accepted and was used in the same form with different materials as time marched on.

I presume in milder climates that no pad was used and probably wasn't for some time. So, having at least some material between you and the dirt was of some benefit. As bags with insulation came about, they were probably warmer on bottom just due to the small amount of loft surrounding the body's pressure points. As pads became en vogue, it became mostly a non-issue as the pad provided the warmth - even if it was physical comfort that was the primary reason for having the pad.

I guess it took ultralight hikers thinking about what weight they could get rid of to produce the quilt as we know it for our use. But it probably wasn't until the relatively recent revolution of hammock camping that real discussions started happening on sleeping bags and how useless the insulation is on the bottom. Bags are a little more useful on the ground just because they get some loft in between pressure points. The hammock spreads out the body pressure points over a larger area, and thus crushes more insulation. It probably took that difference to spark the discussion, and the realization of the bottom insulation issue with bags, which obviously is still not so obvious.

[La Picker]

This makes sense, so then why are full blown sleeping bags so prolific?

Put simply, when sleeping inside a tent on the ground you never have a cold wind blowing underneath you.

[jamaulwall]

In my opinion, the integrated hood is the only advantage to a mummy bag (on the ground or in a hammock) when compared to a top quilt and that only applies in cold weather. To me, that isn't worth the weight, or the restriction of a mummy bag. I wear a beanie and/or use a down jacket with a hood to make up the difference and do just fine. Having said all that, I had never even heard of a top quilt until I got into hammock camping. Since then I've learned that a lot of guys use them on the ground as well (that's why some manufacturers include pad straps). Dealing with scouts I get the impression most people believe a pad is for comfort and don't even think about its insulating properties. A sleeping bag is what they have always known so that's what they use. We are always explaining to new scouts that the pad is for insulation, not comfort. That it provides some relief from the rocks and roots is a bonus but not the main purpose of a pad. Now, with a hammock I get above those rocks and roots and it's not a problem anymore. It's really about the perception and what people are accustomed to. They don't think about the little things unless they get really into going lightweight and then you find the quilt market. Just my thoughts on it.

[Liberty Guy]

I just bought a used Stevenson Warmlite triple down sleeping bag and have already used in my hammock. It is designed without bottom insulation but a pad pocket. works great for both hammock camping and on the ground camping. The nice thing is it has an insulated head area which can be cinched up like a mummy hood if desired. So best of both worlds.

[hutzelbein]

This makes sense, so then why are full blown sleeping bags so prolific?

Because they're warmer than quilts. I tried a top quilt (in the hammock) first, but I was never able to seal it against all drafts - especially when I was moving a bit. That's why I returned to sleeping bags. I use a semi-rec sleeping bag without hood. This means I can zip it open and use it as a blanket when it's very warm. I can zip the footbox closed and use it as a top quilt when it's mild. But when it's cold, I zip up completely.

There's another issue I keep having with differentially cut underquilts. No matter how tight I set them up, they will never touch the hammock in all places. I don't notice that until temps go below ~60°F, but the colder it gets, the more I feel that there are small gaps. I sleep very cold, though. I think normal sleepers won't notice it that much - if at all. But if I have parts of my sleeping bag under me, it closes these tiny gaps. Most of the insulation is compressed, but the parts that aren't make a huge difference to me. It's the same thing when I sleep on the ground. I can only use a top quilt in warm weather.

[Dcolon13]

Someone correct me if I'm wrong, but my understanding about the ineffectiveness of sleeping bags in hammocks also has to do with the hammock compressing all of the insulation because the fabric hugs you. On the ground, there is less area in contact with the ground (less compression) and you usually have a pad.
Also, there have been available for a while sleeping bags with most insulation on top. I've got a 10yr old Big Agnes with a pad pocket and hardly any bottom insulation.

[Tony c]

I bought the thermarest Auriga quilt which is a ground designed quit (works ok in the hammock).

The main differences between the ground based quilt and hammock quilt is draft collars. There's a generous tube that sits on the floor and seals the quilt from drafts on both sides. That mitigates the problem with skinnier hammock quilts.

The other issue is that sleeping pads are skinny and you can roll off the pad. You need to strap your quilt to the pad. At least up to the knees.

Using a quilt instead of bag makes it so much easier to get up. And it's easier to vent/cover than a bag.

[cougarmeat]

This will probable "second that" to a lot of comments above. When you are on the ground, a flat surface, the sleeping bag insulation hugs you better with no gaps. If you use a TQ on the ground - and there is nothing wrong with that, you may need to put more focus on hugging the quilt to your body and keeping it there. I would not use my TQ if I were ground sleeping in the winter.

But in a hammock, because of the way the sides hug you, it is easier to keep the TQ "tucked in". And HQ has a nice snap at the head end that makes sort of a draft collar. And if you have an UQ, that's hugging you from below. So that TQ is getting a whole lot of help in keeping you warm.

The only disadvantage I see in using a sleeping bag as a TQ is a bit of extra weight. But remember this, long, long ago, before there was 850 and 900 fill down, people carried heavier gear. They also hike trails that were uphill in both directions and chewed pebbles for desert and they LIKE IT; but that's a different story.

So it's fine to accumulate your gear so it is ultra, ultra light. But that's a decision, not a requirement.

If you are going to use a sleeping bag in a hammock as a sleeping bag and not a TQ (unzipped), stand next to your hammock and step into your sleeping bag first, holding it up to your shoulders. Then sit in your hammock and bring your legs in. You may find that procedure much easier than trying to "Undulate" your way into the bag once you are prone in the hammock.

[Durtsurf]

I have a quilt and a couple different sleeping bags and most often use one of my bags. They are more comfortable and warmer. Only if I really want light weight because the trip involves a lot of miles do I bother with the quilt.

Because like all other things in life perception is 90% of demand in sales. Why are jacked up trucks and SUV's so popular with people that would never go off road and take a speed bump at .05 mph? Why are political candidates looked up to...for any reason at all by any sane person. Why are McDonalds so prolific when the food is quite indisputably horrible for you?

Tradition, Familiarity, Comfort, and pure and simple not knowing that quilts even exist are all reasons why most big manufactures have only tip toed around quilts.

[Durtsurf]

I think that makes sense. To help with that if you are going to use a bag on a hammock, use a air mattress as well. That kind of supports you up leaving room for the bag to insulate around the sides. And of course you should use an insulated pad.

Someone correct me if I'm wrong, but my understanding about the ineffectiveness of sleeping bags in hammocks also has to do with the hammock compressing all of the insulation because the fabric hugs you. On the ground, there is less area in contact with the ground (less compression) and you usually have a pad.
Also, there have been available for a while sleeping bags with most insulation on top. I've got a 10yr old Big Agnes with a pad pocket and hardly any bottom insulation.