CRUD! Think I bought the wrong sleeping bag at 50 degrees ...a newb error...help?

[Crusinsusan]

So, I hate mummys, and found the Chinook Thermopalm Rectangular Sleeping Bag, and I "ass-umed" it was a 32 degree bag because the others I'd seen were, but the temp wasn't noted on this bag, and I'm fairly certain that when it arrives I will find that it is the 50 deg bag (as I have now found is out there). Tried to save some bucks, and bucked myself I guess.

My question is, will it be okay for a thru hike on the AT (I guess in May 2014) ALONG WITH my


Thermarest womens NeoAir Xlite 66”x20, R value 3.9, 2.5” thick? I don't really understand the R value ratings, you see.

Tyvek on ground too, with Luna Solar.

Am I just a thinking too much, or could I freeze my butt off?

[Darwin13]

leaving in may, probably be fine. But leaving in May most likely means you will be hiking into October if you are not fast or not wanting to go fast. So if you're going NOBO, the Northeast in October is colder than 50 degrees at night.

[Wise Old Owl]

Ya too late to return it or refused?

[Crusinsusan]

Oy. So the pad with R value of 3.9 won't matter?

It's on it's way to me now,....guess I could return it for the 32 degree.

[wornoutboots]

You may want to look into something rated a little lower than 32

[mother goose]

I wouldn't hike any trail any where in March, April or May without a 15 degree bag, in the mountains in the spring night time its cold

[Crusinsusan]

Ah. I'm so glad I asked.....will get a better one. Thanks for keeping my butt from freezing.

[Nutbrown]

That's a wise idea. I'm from Fla too, and a northerner's idea of a chilly night is my idea of frost bite.

[terryg49]

consider adding a sleeping bag liner . Only a pound or so and can add a lot of warmth to your sleeping bag. Send it home when the nights get warmer

[Crusinsusan]

Actually, that's a good idea...adds versatility.

[Crusinsusan]

Hmm....and I think I'd keep it all the way....for hot nights...the combo might be needed again in maine.

[Wise Old Owl]

No don't - I have seen similar stuff at Walmart for cheaper - send it back

[Crusinsusan]

actually, reading around the web, it seems liners are highly suspect for the amount of warmth they offer in real-world use, and nearly all that would account for how many degrees I'd have to make up, are for mummys.

So....now I need to find and UL 15-degree rectangular bag. Bet I'll have to start another thread, because I can't find one under 2 lbs. (I have scoliosis and degenerative disk disease, thus UL + comfort is paramount.

Thanks again all...learning much here.

[MuddyWaters]

Insulation, ALL insulation, basically works by trapping air in small spaces, preventing it from "moving around".
Think of styrofoam. Its mostly air, very little polystyrene really.

When air moves around, it transfers the heat it contains from one place, to another.
In un-insulated areas, air expands as heated (at a warm surface) , and contracts as cools (at cooler area) , this sets up air movements based on the density differences.
This is called "convective" currents, and results in "convective heat transfer"
This is what insulation greatly reduces. It traps the air, and prevents it from moving.
Down is exceptional at this because of all the small fluffy tendrills

However, you still have "conduction" that occurs even thru stagnant air layer.

The thicker the layer of stagnant air, the more the insulating ability. The slower heat is conducted thru it.
This is why a sleeping bags loft, equates to the temp rating. Insulation thickness, (as well as insulation quality) is what determines the amount of heat conducted thru it.

So , knowing that DOWN is about the best insulator there is for us.
Also knowing that a 30 degree bag uses 2" of insulation for about 70-30=40F of comfort rating
You can see, the best you can do is about 20 F/inch of insulation.

So, exactly how much insulation could a 1/16" thick piece of fabric provide, even if it WAS down (and its not, its polyester)
Answer....20/16= 1.25F

If you are willing to carry 8oz to 1lb of "liner" for 1F-2F of warmth, there is no help for you.
For the same weight you could have a bag that is 25F warmer.

Marketing gimmick
PT Barnum said it best.

Keeping bag cleaner is a legitimate reason however.
Still not worth the weight though

[HooKooDooKu]

Thermarest womens NeoAir Xlite 66”x20, R value 3.9, 2.5” thick? I don't really understand the R value ratings, you see.

Tyvek on ground too, with Luna Solar.

Am I just a thinking too much, or could I freeze my butt off?





The first thing to understand is that R value is just a scientific measurement of a materials resistance to transfering heat. An oven mit has a MUCH LARGER R value than a paper towel.

The second thing to understand is that a sleeping bag protects you from the cold of the air, but a sleeping pad protects you from the cold of the ground. Sleeping bags keep you warm by providing loft. But when the weight of your body crushes that loft, a sleeping bag provides very little insulation between you and the cold ground.

The amount of R value you need depends upon a combination of your comfort level and how cold the ground can expect to be. So while I can't give you exact number, I can give these ball-park figures. Sleeping pads sold as 3-season pads usually have R values around R 2.5 to R 3.5. Sleeping pads sold as 4-season pads have R values around R 4.0 to R 6.0. I would hazzard a guess that "4-season" is designed for when the ground is getting near or below freezing.

Since it takes time for the ground to warm up or cool off, you can expect the ground temperature to be about mid-way between what the recent night time low temperatures have been and the resent day time high temperatures. Using The Smoky Moutains as an example, in May, day time highs are around 57 and night time lows are 43 (upper elevations). So you could expect the ground to be about 50 degrees in May. But in December, the day time highs are about 37 and night time lows are 21. So you could expect the ground to be 29 degrees. (I would expect the moutains of Maine in October to be at least as cold as the moutains of North Caroline in December).

[Crusinsusan]

Thank you....again, that's helpful.

[fredmugs]

If money isn't an issue check out my bag: http://www.seatosummit.com/sleepingbags/micro.php

The footbox has a draw string so you can open it up and it completely unzips so you can use it like a blanket. It's still mummy shaped at the head but you don't have to stick your head in there either.

[Sandy of PA]

The comfort ratings on sleeping bags are for guys, ladies generally sleep colder. Being from FLA. in my opinion you are most likely going to need a 20 degree rated bag to be comfortable in the Smokey's in May. That is what I am carrying for late May and June, good for me down to freezing. I also have horizontal baffles(down) to allow me to shift the down on hot nights so I am still comfortable at 70 degrees. I don't sleep well if cold.

[Creek Dancer]

consider adding a sleeping bag liner . Only a pound or so and can add a lot of warmth to your sleeping bag. Send it home when the nights get warmer

Most sleeping bag liners only add about 7 degrees of warmth.

[R1ma]

I don't really understand the R value ratings, you see.





R value is measured in (ft^2 x F x h) / Btu.
U factor is easier to understand. It's 1/R, so btu / (ft^2 x F x h) or btu's (thermal units) per square foot per degree Farenheit per hour.

[Snowleopard]

A rectangular bag will be heavy and, if it's down, will be expensive (more down needed). You won't find a true rating of 20F rectangular bag at 2 lb.
You might check out hiking quilts. Ray Jardine has info on 'why quilts?' and make your own kits on his website: http://www.rayjardine.com/ray-way/Quilt-Kit/index.htm Sewing a synthetic quilt is easy and cheap if you can sew at all.

One dealer of hiking quilts: http://www.enlightenedequipment.com/

Most sleeping bag liners don't add much warmth. If it weighs a pound or more it might add warmth, but it's more efficient to buy a warmer sleeping bag to begin with. If you're cold in your bag wear your extra dry warm clothes, but this has limits. If you're using a roomy or rectangular bag, be sure that you aren't getting drafts in the bag.

[SunnyWalker]

Hey crusinsusan: Go to rei.com for ideas at least. They include specs and reviews and all with the products they sell, including of course, sleeping bags. If you don't purchase from them you'll at least get some good ideas and info.

[HooKooDooKu]

I've just purchased some new sleeping bags after doing a bunch of searching around, so here's the insights I can provide:

Unless you want to spend crazy money for something like 900 fill down bags, a good quality 15-20 degree bag is going to weight about 3 lbs while a 30-35 degree bag is going to weight about 2 lbs. (I already had a 3+lbs 20 degree bag so I was searching for something lighter).

What I eventually found was that CampMor has many of the Moutain Hardware UltraLamina series of bags on sale in the $150 ballpark. (There was also a few Sierra Design down bags in the same weight/price range).

I eventually bought a pair of the men's 32 degree UltraLamina (one for me, one for my son) that weight in at 2lb (regular) and 2lb3oz (large). A nice feature of these bags is that they have zippers on both sides that allows you to fold the cover partly down to help cool off in warmer weather.

I would also agree that REI is another good place to find sleeping bags (I just found that this time, CampMor had the better deal for my needs).

[wornoutboots]

Is there an acronym for I Didn't Read This Entire Post Before I Posted? :) there needs to be.

I carry a 15 degree Down bag except for the Summer months. You can always sleep with it unzipped if you're too hot & use it as a blanket but you can NEVER make it warmer.

[Swordpen]

Talk about crud & possibly buying the wrong sleeping bag! I bought online a Marmot 15 degree long UL super spiral $488. I am 5'9" but BMI, yes 36, sigh (working on that).

However, I read this bag stretches to 81" horizontally, thats 6 foot 6 inches SIDEWAYS! I am not, lol 6'6" sideways!

I've been burned by sleeping bag sizes, temp ratings before, & have spent hundreds of dollars on them. I am a restless side-sleeper (arthritis) so I thought this would be great, but as I read more about this bag, I think I am going to be swimming in it & waaaaay too big! Darn!

[Swordpen]

UPDATE:
I got the super spiral, great bag, & really happy with it. It does NOT stretch to 81" horizontally, lol (manufacturer's poor English). Will be taking it in the mountains in 2 weeks. It is light, stretchy, I can even fit my Jack Russell dog in it with me in a pinch for him, in cold weather. Right now, I am using an Inertia X frame in it (with a x lite <- the accordian closed cell foam pad), folded into 3 thickness to support my hips & lower back. The expected temps are 35 degrees at night.

I am a side sleeper, have the Long 15 degree, & its super comfortable, you can actually move/ turn in this easily. Its 15 degree bag, & weighs 2.5#.