I don't know about the "60% in 6 months" statistic, but it is pretty universally said not to store down products compressed and that doing so would negatively impact their effectiveness.

Here are some of the storage recommendations I found for sleeping bags:

MEC: Do not store a down sleeping bag or jacket in a stuff sack. The fibres or down plumules will compress.
REI: Do not store your bag compressed in its stuff sack as this will eventually damage the fill.
Seirra Designs: Never store your sleeping bag in a small stuff stack since, over time, this will reduce your sleeping bag's loft.

I store my bags in large cotton storage bags (something often supplied with down bags).

I don't know 100% about synthetic, but I've done the same with my nice synthetic over-bag too. Interestingly, it appears both the REI and Sierra Designs storage recommendations are intended to apply both to down & synthetic (at least they don't attempt to differentiate between the two).

My sleeping bag is not down and since it will be stored in the car I can't make loft the priority. I'll store it the car in the bag it comes in.

Surely any degradation of its insulating value is unlikely to be the dividing line between comfort and misery or life and death.

I'll chance that hunch.

I've heard that too, thanks for reminding me ... that's why I went with the summer weight bag, there's essentially no loft to worry about compressing. Layering with blankets adds insulation and airspace between layers. The down bag I'm considering still looks comfy, but probably not for compressed storage in the truck.

Wiggy's bags can be purchased vacuum packed and stored that way for years without loss of loft; just give them a shake and over 90% loft is restored within seconds. I'd imagine most synthetic bags can be stored in a compression sack for years so long as they're kept dry. I'm not a fan of down due to the fact that it's worthless when wet, but if you have a down bag and have the room to keep in packed loosely it should stay dry in a car.

Stephen wrote:
would imagine a good shaking would return the loft. Sadly not true; see below.

It was an article in the UK magazine Trail who had test carried out at the university of Sheffield. Can't find the article on line but did find this in the mag: So you would be stuffed if you unpack a bag and expect it to keep you warm the same day:

Dagny wrote
> "Surely any degradation of its insulating value is unlikely
> to be the dividing line between comfort and misery or life and
> death"
True in your case as you are using synthetic. Having the insulation of a down bag halved could be very serious.
This is one of those tragic cases where us gearheads can't justify spending more money; a cheap duvet will be better than the best down bag. Like when my wife collected the free sporks from the supemarket salad counter and pointed out I could throw them away or carry enough for a new one at every meal. So was a BETTER option than a titanium spork. The [censored]!!
qjs

"The squashing only effects the down in the short term. If left unsquashed down will spring back. However, it may take a while to spring back if it has been squashed for a long time. We did a test ages ago and squashed bags down for 6 months, then opened them for a day and they had not fully recovered and their TOG (temp rating) was way down. After waiting for a few days they settled back to normal. So squashing down bags for a couple of days is fine, but if you squash them for months at a time, then they will take a lot longer to recover. We have not got a time for how long they take to recover, as that will depend on the quality of down I suspect. So you'll be fine a weekend. But when storing a bag at home do not squash it. GT

Good to know, but I am going to strike a balance between being prepared, being practical and common sense I suppose.

My sleeping bag may not work as well because it was compressed for a long time, but it sure beats nothing at all. I am not about to leave it spread out everwhere in my vehicle because of a bit of loft. There are other things I need space for in my truck.

Compressed, it fits nice and neat under the back seat. Not compressed it takes up half the space in the back seat.(for real) So I have the basics covered and thats about all I can hope for.

Stephen, I'm going to try and sway you. You don't have to leave it totally uncompressed, you just don't throw it into a stuff sack. So, leaving it in a duffle bag, or something similar, is good enough to keep the loft. Plus it'll allow it to be relatively well contained and keep it clean.

Believe me, we ALL have things we need in our vehicle. Passengers, car seats, FAK's, flashlights, maps, lunch bag, etc.

My new LL Bean 20-degree bag arrived this evening. The bag has a nice carry handle.

Fills a big gap in my winter car preps. Thanks for the discussion, everyone.


.

Based on my own experience, I have a very hard time believing 60% in 6 months, for either down or synthetic. These days I use only sythetic bags. I have several that have been stored for years, in stuff bags, and they still perform adequately. I have a several year old winter weight synthetic bag, which has been stored stuffed. I still use it for snow camping, and it still seems to work well enough. I'm not saying they don't loose any loft from compression, but my in my experience the loss is nowhere close to 60%, and takes way longer than 6 months.

Also, there is a wide variety of synthetic insulation, and one would suspect that some of the newer materials would handle compression better than some of the earlier versions.


Yes, it is very unlikely to be the difference between life and death. In most conditions, assuming you have reasonably adequate clothing, you should be able to survive a night inside a car (dry and protected from the wind) even without a sleeping bag. I'm not saying you will be comfortable or happy, or sleep much, but you will survive the night.

[quote=AKSARBased on my own experience, I have a very hard time believing 60% in 6 months, for either down or synthetic.
********
Yes, it is very unlikely to be the difference between life and death. In most conditions, assuming you have reasonably adequate clothing, you should be able to survive a night inside a car (dry and protected from the wind) even without a sleeping bag. I'm not saying you will be comfortable or happy, or sleep much, but you will survive the night. [/quote]

AKSAR,

The quote you responded to specified DOWN. One of the advantages of a synthetic bag is that they tend to loose less - some of them almost none at all (see Wiggy's bags) partly because they can't be compressed so much. Believe it or not, that is data from testing. Not all the testing has shown the same amount of loss, but all I have seen indicate more than 50%. That COULD be enough to make it life threatning.

A typical set of thickness vs temp is given below.

Effective Temp Army Western Mountaineering
+40F 1.5" 1.5" (3" total)
+20F 2.0" 2.5"(5" total)
0F 2.5" 3.5" (7" total)
-20F 3.0" 4.25" (8.5" total)
-40F 3.5" 5" (10" total)
-50F 4.0"

If you were to have a bag that was designed for -20 weather (using the Western Mountaineering number) and reduced it by 60% you would only have 1.7 inches of insulation. From similar charts that would be enough to keep you warm while doing light work - not possible in a bag inside a car. That could be critical. It would be especially bad if the weather were colder than you anticipated.

Although it is unlikely to be the difference, in most conditions, the idea of equipping to survive is not for the likely circumstance under most conditions. All about the unlikely and the worst conditions.

Even though I love a good down bag, most of the time I use a synthetic one. Particularly where weight and pack size are less important.

Respectfully,

Jerry

p.s. I apologise for the table, I haven't found how to get it to post properly. jf