top quilt question

ok so i thought by watching videos and reading here i would know how to use my brand new top quilt..but alas like with everything else here i have to learn thru experience i guess. so i got my new revelation x and its rated at twenty degrees, knowing its no where near that when i went to sleep last night, I think I should have vented to begin with..but it was so nice and warm..
Anyway, I woke up five hours later sweating and worse yet it seemed that i had condensation on the outside of the quilt.. Is this normal? was I so hot that in fact I caused the outside of my quilt to condensate? I also use a 3/4 uq thats rated about twenty also.. it did get down to about 45 or so for what that is worth..I was so excited and it worked wonderfully perhaps too wonderfully..I am just trying to get the hang of this lol thanks

While it's certainly more economical to have one winter quilt that you can vent when it's warm, it's not as easy as it sounds.

Condensation will form anywhere given the right conditions. I've had condensation form only on the top side of the tarp, only on the underside of the tarp, and on both sides :confused:

In your case, you have hot, humid air coming off you body, traveling through the quilt, and finally hitting the cooler air on the top side of the quilt. That sounds like a good formula for condensation. It's not that you did anything wrong; it just "is."

When I hike, I like to stay "comfortably cool." This keeps me from sweating and soaking my clothes. Soaked clothes eventually make me cold, even dangerously so. The same concept can be applied to sleep.

Were you using a tarp? While a lot of sweat can certainly provide condensation on the sleeping bag regardless, not having a tarp would make it worse. The moisture is looking to stick to something at the right temperature.

Hey buddy, same thing happened to me last night with my 30*. Review's coming, but great question. I see what MAD's getting at; but I'm wondering what role my footpad played, because the condensation was limited only to that area. But man, these things are warm!

If a quilt and what you are wearing will keep you just right at 20F, it might not be quite enough at 10F and a little too much at 30F and even worse at 40F. That's where venting comes in, because as you proved, if you are too warm you are going to sweat. And once you sweat, you luxurious downy quilt might soak up that sweat like a sponge, and I suppose it might even soak through to the outer shell.

This is a completely different mechanism than condensation such as explained by Mad77. As your body continuously gives off insensible perspiration ( vapor ) to keep your skin moist, when this vapor contacts something cold enough ( below the dew point ) that vapor condenses into liquid, just like when your breath hits your cold windshield, or even if it just hits cold enough air. Like when you exhale on a cold day and see your breath. And it can condense on your TQ shell or even the outer layers of the down if they are cold enough.

But here is where a new angle might come in in your case. The reason you sweat when too hot is so your body ( or ambient ?) heat can evaporate the sweat, turning the sweat into vapor, and cooling you down by evaporative cooling. So, this sweat can provide a huge new supply of vapor from your body, which is now available for condensation in your outer layers and on your cold shell. All on top of any sweat that might be soaked into the same. Whoohooo, all this together could flatten a quilt pretty quick!

So, venting is an important skill to learn, as we try to be just right, and not too cold or too hot. But it might be better to err on the side of slightly/barely too cold. So as to avoid that evil sweat in your down. (but it feels so nice to be toasty warm when the other side of the quilt is freezing cold! )

What would be fun is if you had weighed your TQ, especially after several days of being warm enough to sweat.

Its also a reason they make 50, 40, 30 20 and 0 degree UQ's and TQ's. As you hang more and spend more time in the hammock. You will, like the rest of us, buy a bunch of different made quilts for the seasons you hang in over time. No one quilt of any size will work for the most of us no matter how much you vent in the hot times of the year.

if i may interject some science-y stuff:

what youre experiencing isnt sweat essentially on top of the quilt, condensation happens when 2 dissimilar temperatures meet. thats why grass is wet with dew on a cool night, the earth is warm, and why you get rain clouds when fronts of air meet with different temps. what you get is, essentially, heat concentrated on top of your quilt. your body alone outside wont (shouldnt) get wet because your surface temps will drop and "blend" with the air around you. but in a quilt, it is concentrated and rises up to the top of the quilt. depending on the situation, if the temperature of the ambient air at night is similar to the temperature of the surface of your top quilt with you in it and no drops occurred overnight, no condensation. think about how your windshield defroster works when you have the AC on blast in the summer and you get moisture on the outside of the windshield. if you heat it up, the condensation goes away right? thats where venting comes in

whew. ok, so lets figure out what all that means.

if you vent when you first start out in the quilt, you may not be as warm to begin with but you stand a better chance to fight off condensation. a tarp will help, as will things like a hammock sock because it will create a buffer of temperatures in your hammock area. when you have a tarp above you you get a small bit of warmer air between you and the outside air and USUALLY the tarp will take the brunt, even if you get some raining inside the tarp... kinda like when guys that sleep in tents get the same thing because it got so much warmer in the tent than the outside air.

the issue comes when you get condensation on it, you can get soak thru which can hurt the overall effectiveness of the quilts temp rating, and could potentially ruin your gear on top of making for a colder night than you expected. you can run into an issue tho if you have a quilt that doesnt breath at all (ie: sil nylon shell) but something with a DWR outer shell can help keep the down dry.

the solution, overall is have a quilt as close to the temperature expected, and wear clothes or vent as needed since the weatherman is NEVER right.

WOW!!!! alot of help! thanks everyone,, I did more venting last night as i started out and that helped alot:) still had some condensation where i was breathing on it...but not much other then that! still dialing it in
thanks everyone..

If I remember right Shug has to use a bib because his breath was soaking his quilt near his face.