I am a hammock camper but for winer camping top quilt stacking should be the same in a hammock or on the ground. I have a 0 degree top quilt and i am thinking of using a 40 degree EE synthetic quilt over it for below 0 warmth. Any experience with moisture in the down quilt being reduced by this method.

I had a chance to try this out last weekend. In California temps don't get much below 30*. However I stacked an EE Prodigy 40* over a Katabatic Palisades and was roasty toasty all through the night down to less than 30*. I'm a cold sleeper however. No condensation to report in the down quilt, however, there was obvious amounts of condensation build up in the synthetic quilt.
The system works though, no condensation in down quilt!
I would expect your tests to be successful. Good luck.
-James

I've dome similar. I've taken two EE 20 degree quilts and a insulated bivy to -25F. It does help move condensation as much as your outside layer provides. For example a 40 degree synthetic will probably move condensation to about 0F (where the temp inside the quilt is once again below freezing).

Kevin

I've been looking into this as well to extend my winter sleep system, so I'm interested in hearing others' findings, experiences and tips/tricks.

I've got a 15F Katabatic down quilt which keeps me comfy down into the teens with just base layers on. I can push it a bit more by wearing my insulated clothing, but I'd like to be able to extend my system comfortably down to around 0F.

I've been leaning toward achieving this by pairing a light synthetic quilt with my down quilt. The synthetic would help with moisture management (both from condensation and perspiration) in addition to providing some extra warmth. The synthetic quilt could also work stand alone for the warmest of overnight trips in the summer/fall.

I've been looking at the EE Prodigy Quilts in the Reg length/Wide cut; either the 40F or 50F model. I'd appreciate some input from others on what temp rating I should be looking at for the syn quilt; I'm leaning toward the 50F at the moment as I already have another 30F down quilt, so this syn quilt would only be used in combination with another quilt or on its own for those warm summer trips.

I'm also interested in hearing any experiences or advice on how best to attach the quilts or otherwise keep the syn quilt in place on top of the down quilt.

Finally, I assume one needs to size up on the synthetic quilt to fit over the down quilt. If I'm using a regular width and length down quilt, is sizing up to a wide width syn quilt sufficient?

Looking forward to hearing what others have to say. Sorry for the slight, but related, thread hijacking...

If you want to keep moisture out of your down (more important on longer trips) get a synthetic that will keep your down near freezing. It depends what temps you are planning on going down to. I put a thermometer between layers to measure temp differences. I think you could get up to a 25 degree bump with 2.1 apex, but it could be lower.

Sizing, a bit bigger is better, it depends on how tight everything fits. I use a bivy with some synthetic insulation so it's plenty big. Putting the two quilts together wasn't an issue, I just stuff the foot box of one in the other and using the EE quilts I snapped then together at various points. I think I may have more snaps than normal though, as I had Tim put on some extras for me. My quilts are a large, so they had plenty of space.

for stacking a 40F or so quilt/bag .... figure around 15-20F in temp gain ...

down under synth ... i do it all the time with jackets and it works great

@ Kevin,

Interesting point about getting enough synthetic insulation to keep down above freezing temps (for moisture management purposes). I hadn't really thought about it that way.

Food for thought...

I've never tried quilt stacking, so can someone explain to me why the synthetic doesn't squash the down, so loosing loft and warmth?

Thats very interesting.

I suppose that could happen if your synthetic was to small or very heavy. In my case, a lightweight insulated bivy is not any more of an issue than a standard bivy.

Regarding keeping the down above a certain temperature or at least near freezing, I do not know if it is an issue, but I could see it being an issue, more so on longer trips that never warm up, and thus a possible need for a vapor barrier, or at least being aware that some moisture will get in there when temps hit a certain level.

Remember, you can compress down by around 50% of its original loft and it still retains all of its insulating properties. That number is by memory, so it may be a bit off. There's a thread about it somewhere...

Edited by T.L. on 02/20/2013 13:28:44 MST.

While originally I planned to do quilt-on-quilt experimentation this winter, I ended up getting a Thermarest Altair bag so used quilts with it to take to down to -24 F so far. My son also used a quilt over a bag on one winter camp-out.

I have not really seen any great amounts of condensation being trapped in the over-quilts. The coldest night to date was with the Altair bag with a Thermarest Alpine Blanket over it. There was tremendous amounts of condensation from my breath and a layer of ice built up at the top of the quilt. Arond 1:00 AM I woke up and realized that I was sweating. Funny to be too hot at -24 F. I loosened the chest draft baffle in the bag to vent some of my body heat and went back to sleep. A couple hours later I woke up to the feeling of water dripping on my face. My face and neck were wet and I found that my left shoulder and half-way down my arm was soaked.

During turning in my sleep I opened the bag enough to really get the warm air coming out which melted the ice rime that had been building all night. I took a picture of myself to look at later as it was too dang cold to mess around. I decided not to put on a new shirt and just went back to sleep.

In the morning my shirt was dry, so my body heat evaporated it and pushed it out. I could not see any sign of ice "inside" the over-quilt, but there was of course still quite a bit at the top.

One of our fellow members had asked me to check the weight so I weighed them both soon after getting in. The over-quilt had picked up 0.85 oz (24 g) in weight and the bag was 0.92 (26 g) more than when I got it.

I don't think either would have been so high if I had not soaked my shirt. I will attach the picture as it shows the amount of soaking seen by the darker color of the wool blend.



That has been the worst time with it. My son and I both have also used a Jack 'R' Better Sierra Stealth as an over-quilt and have seen no condensation build up in the body, only at the top from breathing.

@Travis : interesting figures in the current article on Wind Insulation, including : "when your insulation is 50% the thickness, your actual insulation value could be only 40%." And : "High lofting down like 800 down will compress more rapidly than denser insulation such as 600 down, 500 down".