30 degrees backyard test worked

**nogods** · 11-11-2007, 10:42

With a predicted low of 31 I decided to get in a backyard cold weather test and it worked just great. When I crawled into the Claytor at 11 pm there were ice crystals on both sides of the tarp and my thermometer read 28, but I just checked the online weather station at the elementary school about a mile from my house and their lowest reading for last night was 30.

I put a cheap Mylar space blanket in the pad pocket, then put my homemade spe over it (also in the pad pocket). The home made SPE is just a Walmart blue pad with 10" wide pieces of another Walmart blue pad tied to the sides.
I also had my homemade weather shield covering the claytor. Pics of setup:

I decided to try this rig without the big agnes insulated air mat. I dressed as I usually do for sleeping outside in the winter - wool socks, mid-weight polyester/merino wool long johns, a polyester hooded sweat shirt, and a polyester fleece. I used my 20 degree synthetic North Face dolomite bag as a quilt and also wore a polyester skull cap.

I was very comfortable and experienced no condensation except on the side of the weather shield directly in line with my mouth after I had turned on my side. There was no condensation between me and the pad (which, of course, were separated by the pad pocket) and no condensation under the space blanket.

I don't know if the space blanket made a difference, but when I rolled back onto my back from the side sleeping position, the portion of the bag that was covering my back ended up under my back. When I woke in the morning I immediately checked under my body for condensation and found that both sides of the part of the bag I had been sleeping on was as warm as my body.

However, as I was taking the pictures this morning, my back and head rubbed against the tarp and I was soaked with the now defrosted ice crystals I had notice on the inside of the tarp the nigh before. These droplets started falling onto the hammock. The weather shield protected the hammock from them, but if I didn't have a weather shield I might have ended up very wet inside the hammock from the ice that crystallized on the inside of the tarp.

I'm hoping that was caused by evaporation from under the deck on which I had set up the hammock. The ground under the deck is covered with plastic to keep anything from growing there and it probably had collected some water from the rain we had the last few days.