Is it my tent or is this normal???

[MEB]

Last night I decided to tent out in the backyard. I slept great but when I woke up the inside of my tent was all wet as well as the top of my sleeping bag. The temperature last night was in the low 30's. My tent is a Big Agnes SL1. It's a double walled tent and perfect for one person....but why is it so damp? I've never had this problem when I stay out in my two person tent.

-MEB

 

[blacknblue]

It's probably just the moisture from your breath. Every exhalation throughout the night while you sleep adds water vapor into the air. Unless the tent is well-vented, condensation build-up is the result. A two-person tent wouldn't be as bad just b/c there is more air to saturate. Same goes for the sleeping bag. My Mtn Hardwear BB sleeping bag is black in the upper chest area for the purpose of drying out quicker in the sun.

If it had been a little colder, you would have had frost feathers inside the tent! There's nothing quite like waking up, rolling over, brushing against the tent, and being showered by ice crystals first thing in the morning.

 

[Pete_Hickey]

..... The temperature last night was in the low 30's. .........but why is it so damp?

I'll bet the grass was covered with dew (or frost) as well..... and the grass wsn't even in the tent.

 

[Guinness]

Hi MEB,

Actually that is normal. During the night, a person can exhale up to 1 liter of water. The vapor will naturally adhere to any surface that is cooler. Any tent can allow some vapor to pass through it's fabric as long as conditions permit such as adequate air flow and the current dew point. The size of the tent plays a part bringing the wall closer to you where your exhale reaches it sooner allowing it to condensate.

I use small tents during winter all the time and if I do not leave the window and door open, major condensation forms. Then when you wake up and touch the walls it feels like a snow storm inside the tent.

 

[Chip]

That's a WELL ventilated tent IF you staked out the fly properly, including the clips that draw the side walls out. Maybe because it was your backyard you didn't tighten everything up well ?

 

[Jay H]

Depending on how cold your sleeping bag is rated versus the predicted temperature and how you like to sleep, on a regular tent with rainfly, you can simply sleep without the rainfly on to ventilate well.

If it gets real cold, like blackandblue mentions, you can get icycles on your bag if you have it tucked up against your face.

Jay

 

[dug]

Over-bagged and if the tent was zipped up, yeah it's normal. Sleep with the door open.

 

[John H Swanson]

I'll bet the grass was covered with dew (or frost) as well..... and the grass wsn't even in the tent.

This joke made my day. Thanks

 

[DougPaul]

Three possible solutions:

1) Stop breathing. (Or at least, exhale outside the tent.)
2) Lower your body temp to or below ambient.
3) Ventilate.

Doug

 

[MEB]

Thanks for all the good information! I had the tent well staked out but I did have the fly closed...next time I'll leave the door open to see if that helps too. As far as not breathing....well, I guess than I would not have the problem to begin with

-MEB

 

[dr_wu002]

Three possible solutions:

1) Stop breathing. (Or at least, exhale outside the tent.)
2) Lower your body temp to or below ambient.
3) Ventilate.

Doug

4) Wear a full astronaut suit. I know several people who bring these hiking. Or also, you can hike with a coffin and sleep in that.

-Dr. Wu

 

[Papa Bear]

Hi Mary Ellen

I know that tents can differ considerably in their ability to ventilate. My SD (two layers separated by an air space) does quite well, but as the temperature drops and the humidity is high it becomes hard. I have the SD Lightyear, and I've used it down to about 20 degrees with reasonable success (after all, it's a summer tent) but I never tried below that. If it's not going to rain (and it's not too cold) pitch it without the tent fly.

It also should help to orient the tent along the direction of the breeze so the air can flow in the back and out the front.

 

[John H Swanson]

Three possible solutions:

1) Stop breathing. (Or at least, exhale outside the tent.)
2) Lower your body temp to or below ambient.
3) Ventilate.

Doug

4) pipe your breath outside the tent
5) heat the tent above the dewpoint - it will be need to be very hot and very humid, but no condensation.
6) eliminate the tent walls - use a tarp (my favorite)

 

[MichaelJ]

If it gets real cold, like blackandblue mentions, you can get icycles on your bag if you have it tucked up against your face.

Or even worse, a ring of icycles around my face, with the nearest ones melting from my own escaping body heat, thus giving me a wet face for morning. Yuck!

 

[dug]

Or even worse, a ring of icycles around my face, with the nearest ones melting from my own escaping body heat, thus giving me a wet face for morning. Yuck!

Or, it snowed more IN the tent than out.....

 

[Chip]

Is it my tent or is this normal???

That amount of condensation in a double-walled tent is not normal (normal being my experience with a number of tents in various temps and numbers of people over the years). The condensation and snow-flaking occurs on the fly, not inside the tent. That's a major feature/benefit of a double-walled tent.

If the bottom of the fly was in contact with the grass, then you cut off the circulation that would normally draw the moisture away from the mesh.

 

[MEB]

Hey Chip,

That's why I went with the double walled but the condensation was on both the fly and the mesh inside. I have several other tents but this is the first one where I've experienced the dampness on the inside mesh. I'll have to set it up again to see how far the fly was from the ground too.

-MEB

 

[una_dogger]

I think Pete Hickey may be right about the grass being a factor. Do you normally only camp in the forest -- just thinking the forest floor is usually pretty dry in the am and grassy lawns are dew covered.

 

[Rick]

I have experienced time and again what BnB mentioned in post #2. However, it is all anecdotal and I have no scientific experience to back up any of this.

I have horrible condensation in my small 1P tents, even when guyed out thoroughly, as compared to my 2P tents. Especially on colder nights.

I believe the vapor from your breath (and what migrates through the bag) is much more condensed in the small amount of open air in a smaller tent and hits the wall and condenses into much more than it would in a larger tent where the moisture/vapor can mix with drier air and form more air with a less condensed vapor.

Over time, I have found that unless it is bitterly cold (frost-feathers) or cold wet and windy, I tend to try to keep as many doors/windows open as possible.

I have also found (This is anecdotal rather than scientific) that tents with poles that set up through continuous mesh sleeves rather than clip designs usually don't allow air to transfer as well.

 

[spider solo]

MEB: Good to see your sleeping out and seeing how your tent is working out etc...
The small area of the tent is probably a big factor, along with humidity and relative dew point etc .etc., most of it eventually gets me confused and I do like many say and sleep with the door open.

I also slept out last night in my yard as I often do, these days sans tent.
it's a good way to see how "waterproof" my sleeping bag is and how is it to pack up wet from the overnight... things like that.

It's surprising how much you can learn just by doing some "camping" in the yard...stuff like how cold can I use my stove ...can I use it with gloves on etc.? Can I set up the tent wearing gloves..or gloves and snowshoes later in the year...

Sleeping out about once a week or so... works out to approx 30 nights a year for me ... finding it a big help....