Condensation on Sleeping Bag

Ok I've had a recurring issue for the last few months. Almost without fail I have woken up to my sleeping bag being wet in the mornings.
I have used a few tents and a tarp and it has happenned in each of them. It has happened in two sleeping bags but more so in my winter bag. Has anyone experienced this?
I will post up some of the conditions it has occurred in below:

So the two tents i have used are an Exped Cetus UL II and a Macpac Minaret (both with vents opened). I have also now used it with a 3x3m Tarp in both a 3 side closed pitch and a standard a frame (using a polycro groundsheet).

I started noticing it in my Macpac Epic 600 first. It was happening in the Exped in fine weather. It seemed to be less prominent when i used the bag as a quilt. It did this on 4 or 5 trips from pouring rain to blue bird days. Its never been enough to get me cold and it seems limited to the outer fabric and the top maybe cm of down as it drys very quickly even in fairly humid conditions. It is however a pain as it means gear has to be aired out midday while hunting.

I then tested in in my older Macpac and the same thing happened. This was only tested 2 nights in fairly hot days and cold nights (20 plus in the days and freezing tarns in the morning).

I have also slept in the same tents in my little Aegismax Sleeping bag which is stupid light rated at like 10 degrees i think. It didn't get as wet but the the second night it did and it got wet enough that my feet where killing me. Trying the Aegismax mostly in Tarps but also in the Exped. It definitely was better and maybe 50% of the time i woke up dry. The only issue is when it got wet i got cold and it doesnt dry near as fast as the hydrophobic down in my macpac.

Not sure it im just way to hot a sleeper or what but its getting a touch frustrating.

You don’t have this problem at all, when sleeping in your own bed?

are you using a liner???

I can see this thread going so far SOUTH:XD:;)


Is your sleeping bag touching the tent?

Try opening the bottom. Do you sleep with a woollen hat on? Take this off and try to regulate your body temp by putting a hand foot out to cool your self down a bit.

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Originally Posted by Maca49

You don’t have this problem at all, when sleeping in your own bed?

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Nope thank God if it started happening at home it would confirm I'm just nuts

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Originally Posted by Micky Duck

are you using a liner???

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Yes using a Silk macpac liner have tried with and without it.

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Originally Posted by Sideshow

I can see this thread going so far SOUTH:XD:;)


Is your sleeping bag touching the tent?

Try opening the bottom. Do you sleep with a woollen hat on? Take this off and try to regulate your body temp by putting a hand foot out to cool your self down a bit.

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Hahahaha lets see I think you might be right. At least that way i get to laugh at it! Sleeping bag is not touching the tent. Maybe a little when i have two people in it but definitely not with just me and definitely not touching the tarp as in a frame i have a good two feet clearance.

Maca49s question is not without merit......do you end up with wet sheets at home EG do you sweat like a .........hot person,during the night???

have you tried the budget lightweight sleeping bag from the closet just to see if its you overheating????
I get condensation with an old school army cover but its nowhere near as bad as what you describe...the only time Ive seen anything like what you are saying is with a homemade cover with non breathable fabric...that got chucked quicksmart.

Yes the same happens to me in colder weather. I find if I leave it in the tent with some airflow through it during the day it's mostly dry by the next night.
And I give it a good airing when I get home

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Originally Posted by Micky Duck

Maca49s question is not without merit......do you end up with wet sheets at home EG do you sweat like a .........hot person,during the night???

have you tried the budget lightweight sleeping bag from the closet just to see if its you overheating????
I get condensation with an old school army cover but its nowhere near as bad as what you describe...the only time Ive seen anything like what you are saying is with a homemade cover with non breathable fabric...that got chucked quicksmart.

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I sleep hot but not sweaty. Don't have another cheap sleeping bag but the Aegismax is lighweight budget. only 295grams of down. Its this one https://www.youtube.com/watch?v=MY1bJPSZWnY

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Originally Posted by Backcountry Bob

Yes the same happens to me in colder weather. I find if I leave it in the tent with some airflow through it during the day it's mostly dry by the next night.
And I give it a good airing when I get home

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I found the same but I dont often camp in one place for more than a night so i dont have a choice but to pack up. If i dont set up early enough its not dry by night time or if it raining it doesnt dry a few days. Its doesnt make my cold more of an annoying type thing.

do you perhaps go full on mummy style...eg pull drawstring closed and its your breath condensing????
got me stumped as Im a hot sleeper,normally have at least and arm and head out of bag...but dont have issues like you are having.

Are you cooking or making a brew with tent closed up.

https://sectionhiker.com/vapor_barrier_clothing/

maybe something to consider, depends on what side of the coin you view,
my understanding they are used more in dry cold alpine climates

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Originally Posted by Micky Duck

Maca49s question is not without merit......do you end up with wet sheets at home EG do you sweat like a .........hot person,during the night???

have you tried the budget lightweight sleeping bag from the closet just to see if its you overheating????
I get condensation with an old school army cover but its nowhere near as bad as what you describe...the only time Ive seen anything like what you are saying is with a homemade cover with non breathable fabric...that got chucked quicksmart.

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That’s why I asked, if it was happening at home I’d be off to the Doc for a check up!

You probably don't want to be looking at a new bag the Montbell bags have a POLKATEX water repellent on it which I have found great for the condensation and light rain beading straight off the bag.

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Originally Posted by Micky Duck

do you perhaps go full on mummy style...eg pull drawstring closed and its your breath condensing????
got me stumped as Im a hot sleeper,normally have at least and arm and head out of bag...but dont have issues like you are having.

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Nope no hood on the Aegismax at all I usually wear a Merino beanie to bed. I might see if dropping an arm out helps only thing is temps are dropping again so not sure if that will work if I want to sleep. Its got me stumped too. To be fair i will get to spend some time in a cold but dry environment next November so will test it out then.

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Originally Posted by PillowDribbler

Are you cooking or making a brew with tent closed up.

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I wont even cook in the tarp now as I'm paranoid about this condensation. I also completely swap cloths before bed and put all my used clothes in a dry bag under the vestibule or right near the front of the fly.

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Originally Posted by striker

https://sectionhiker.com/vapor_barrier_clothing/

maybe something to consider, depends on what side of the coin you view,
my understanding they are used more in dry cold alpine climates

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I will look at this more. I have used a mylar bag before on a trip a tent got destroyed but put the bag inside. Might give this a go.

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Originally Posted by Maca49

That’s why I asked, if it was happening at home I’d be off to the Doc for a check up!

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I might try this even I have had thyroid issue in the past so maybe its being triggered in the cold or something.

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Originally Posted by possum_shooter

You probably don't want to be looking at a new bag the Montbell bags have a POLKATEX water repellent on it which I have found great for the condensation and light rain beading straight off the bag.

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Not really have brought a tent and a fly trying to solve it. Also the macpac is water repellent and has dwr coated down. It is very good and seems to keep the moisture in the outer part of the bag.

stop watching porn before bed time :P

Interesting thread. Hunted with 2 different people over the years who had fairydown 20 below sleeping bags. They would wake up most mornings without fail with the outside of their bags wet, more so in colder weather.
Ive used several different makes of bags over the years and have only encountered this problem with a marmot lithium sleeping bag, heavy bag for winter use only... Although this bag has hardly been used, I dont use it anymore.
Currently using a mamot phase 20 plus macpac bags without any issues..

Have you contacted macpac to see if they can shed any information on what maybe the cause of it????

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Originally Posted by gonetropo

stop watching porn before bed time :P

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There’s always one:redbullsmiley::P

Sometimes suffer the same thing, fucking frustrating when moving camps each day

A thought that just popped into my head - is your sleeping bag being stored in a dry environment? Could it be taking on some moisture at home and then it’s coming out when you heat it up?


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best guess is poor airflow in tent with condensation latching on to everything that's cold, tent walls and bag exterior. The problem is the bag is too good and none of your body heat is getting through. One of the reasons I moved on to hammocks and tarps.

It’s just simple condensation. Obviously your bag is warming right through to outer shell and cool moist air, in the tent is condensing on outer shell. Slap a lightweight waterproof tarp on top of bag or start using a bivvy bag.

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Originally Posted by Smiddy

A thought that just popped into my head - is your sleeping bag being stored in a dry environment? Could it be taking on some moisture at home and then it’s coming out when you heat it up?

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I was just wondering about that too.

As far as I can remember I've only had wet top of sleeping bag in the morning is when I've been in a bivy bag or under open skies and got dew on it.

With a good bag in cold conditions I've had frost/ice on top but the bag insulated well enough that it didn't melt.

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Originally Posted by gonetropo

stop watching porn before bed time :P

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I like to leave it playing at night too it helps me sleep.

Are you fully closing up the tent at night? I have found that built in vents are almost never sufficient on their own. I tend to leave the insect mesh exposed and air gaps between fly and inner.




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Originally Posted by Cliff

It’s just simple condensation. Obviously your bag is warming right through to outer shell and cool moist air, in the tent is condensing on outer shell. Slap a lightweight waterproof tarp on top of bag or start using a bivvy bag.

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Expensive exercise to go buy a bivvy bag just to test the theory. I will try a top sheet maybe.

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Originally Posted by YosemiteSam

best guess is poor airflow in tent with condensation latching on to everything that's cold, tent walls and bag exterior. The problem is the bag is too good and none of your body heat is getting through. One of the reasons I moved on to hammocks and tarps.

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I dont think its this as it happens with my tarp. I dont think you will find a more freeflowing tent than a tarp set up as an A frame.

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Originally Posted by Smiddy

Sometimes suffer the same thing, fucking frustrating when moving camps each day

A thought that just popped into my head - is your sleeping bag being stored in a dry environment? Could it be taking on some moisture at home and then it’s coming out when you heat it up?


Sent from my iPhone using Tapatalk

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I've hung the bag up in the wardrobe now to see if that helps.

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Originally Posted by kiwioutdoors

Are you fully closing up the tent at night? I have found that built in vents are almost never sufficient on their own. I tend to leave the insect mesh exposed and air gaps between fly and inner.

Sent from my iPhone using Tapatalk

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I usually leave the vestibule open partially if possible and have tried with a tarp that has great ventilation.

Quote:

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Originally Posted by Cliff

It’s just simple condensation. Obviously your bag is warming right through to outer shell and cool moist air, in the tent is condensing on outer shell. Slap a lightweight waterproof tarp on top of bag or start using a bivvy bag.

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Just to clarify, I don’t think it will be moisture from the outside air, as this would only condense on cooler surfaces (think beer cans). What’s happening is interstitial condensation, similar to what happens in the walls of a house.

Air heated by your body gets drawn to the outside, taking vapour with it. As it contacts the outside it cools and can’t hold as much water, so it dumps it. Look up ‘relative humidity’.

If you’ve got condensation on the outside then the bag is doing it’s job, and not allowing it to wick back into the absorbent filling. More of a worry if the condensation occurs on the inside of the outer shell.

You should dry it as early as possible though, DWR coatings can only do so much. If you must pack it up damp, then take it out as soon as you set up your next camp.

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Originally Posted by mopheadrob

Just to clarify, I don’t think it will be moisture from the outside air, as this would only condense on cooler surfaces (think beer cans). What’s happening is interstitial condensation, similar to what happens in the walls of a house.

Air heated by your body gets drawn to the outside, taking vapour with it. As it contacts the outside it cools and can’t hold as much water, so it dumps it. Look up ‘relative humidity’.

If you’ve got condensation on the outside then the bag is doing it’s job, and not allowing it to wick back into the absorbent filling. More of a worry if the condensation occurs on the inside of the outer shell.

You should dry it as early as possible though, DWR coatings can only do so much. If you must pack it up damp, then take it out as soon as you set up your next camp.

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Agree in part, there'll be a heap of different forces at work, in short the bags wetting out (from a form/s of condensation) and as Stocky mentions that moisture is wetting through the down as well.

Other things to consider, are you sleeping in dry clothes (?) damp clothes will produce more vapor. Are you going to bed hot and filling bag with vapor quickly? Sometimes sticking an arm or leg out to cool down, results in your body feeling the limb cooling down, fires up the furnace to protect the core and voila, you're producing more vapor.

As some others have said it’s warm moist air condensing on a cooler surface. The physics of sleeping in a tent!

Try to reduce the moisture you take inside inside the tent eg wet boots, pack, clothing, cooking etc and try maximise ventilation to remove the moist air (you breathe out a heap of it overnight) by opening all vents, raising the fly if poss and leaving doors open to increase air flow
Where you pitch can also cause issues eg next to streams, on wet ground for example.

A trick you can do if it’s mainly wetted down at your feet (from brushing up against the inner fly) is to zip up your waterproof jacket and slide your bagged feet into the bottom of the jacket. Keeps the outer bag dry. Hope this helps...

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Originally Posted by mopheadrob

Just to clarify, I don’t think it will be moisture from the outside air, as this would only condense on cooler surfaces (think beer cans). What’s happening is interstitial condensation, similar to what happens in the walls of a house.

Air heated by your body gets drawn to the outside, taking vapour with it. As it contacts the outside it cools and can’t hold as much water, so it dumps it. Look up ‘relative humidity’.

If you’ve got condensation on the outside then the bag is doing it’s job, and not allowing it to wick back into the absorbent filling. More of a worry if the condensation occurs on the inside of the outer shell.

You should dry it as early as possible though, DWR coatings can only do so much. If you must pack it up damp, then take it out as soon as you set up your next camp.

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I agree with @mopheadrob. If the 'moisture' is not the result of masturbation and flatulence then it must be condensation, formed when the warm moist air hits the 'dew point' on the cold outside of the bag. A solution would be to lay a brush cotton sheet over the bag while sleeping which will slightly insulate the outside of the bag thus moving the 'dew point' to the top surface of the sheet instead of the bag. You will have a wet sheet in the morning but a dry bag, you dirty depraved deer shagger.

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Originally Posted by gonetropo

stop watching porn before bed time :P

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Interestingly, Heath Ledger complained of sleeping bag condensation whilst making a certain movie