Last night it was sufficient cold to test the system with My official winter gear. At 22:00 a clock it was -22 C (-8 F) and during first four hours it stayed that way. About 02:00 temperature started to rise because of the weather front which will bring us more snow. Weather front is now about 200 km from us and the temperature is -12 C (10,4 F).
As I said I used the full winter gear set which I'm going to use in my spring trip to Lapland. The base system was same as in first post (hammock and double SS + OC).
My clothes: Cotton boxers and short sleeved cotton T-shirt, Fleece jacket, Fleece trousers, cotton socks, wool socks, cheap down jacket, gloves, winter cap, hood made of silk.
Sleeping bags: Down bag with Quantum fabric and 800 g down as a quilt and a very large synthetic bag with two layers of 250g/m2 insulating fabric called hollowfiber. Not very high tech.
The idea behind the big synthetic bag is to keep it under me and around my sides. It has zipper right in the middle of the upper surface and the circumference is 150 cm so the down bag does not compress too much if I would have to close the Big bag. The other idea is that the synthetic bad should take all the condensation and so the down bag should stay drier.
Pad: Thermarest Deluxe measuring about 192 cm x 90 cm x 3,8 cm. And it weights about 1250 g.
I went in wearing all my clothes. Down jacket has a quite good hood, so it was also in use. It took some time to organize the pad and the Big bag under me. When I went in there was not very much of a room, first I thought it would be a tight fit but after all settled down hammock was almost as roomy as normally. Then I put my feet in to the down bags feet compartment and then in to the Big bag. The down bag was upside down as a quilt. I did pull the Big bags zipper up to about my knees and started to wait if the could would come.
At this point the temperature inside the hammock was about -4 C (25 F) and temperature outside was about -22 C (-8 F).
After a while I noticed that my knees were sweating, also my back and groins were little sweaty also. So I started to loosen up. I opened the down jacket, took the hood away, took away silk hood, opened the fleece jacket and took away gloves. And then I tucked the down bag to my side. I was laying there only the cotton shirt over my torso and simple winter cap in my head. I did keep the jackets on but they were totally open. Also the fleece trousers I kept on. I also had to open the Big bags zipper again. I kept my feet inside those two bags.
At this point the temperature inside rise, it was about 5 C (41 F). Outside temperature was at this point still -22 C (- 8 F). I was laughing out loudly. It was very funny feeling. There was 27 degrees of Celsius difference in temperatures inside and outside. Who would have thought it possible? I was sleeping in hammock at such a cold weather and I was sweating.
After the initial extra heath was gone I zipped the fleece jacket closed again and did put down hood over my head. And also I did took down bag quilt over me again.
At the morning about 08:10 a clock temperatures were as follows. Outside -12 C (10,4 F) and inside the hammock there were about -4 C (25 F)
There were condensation mostly at insect net. Over cover was totally dry. The condensation was minimal. I have seen thick condensation layers inside tent fabric after similar winter night covering large areas in such way that bags and clothes will get wet when exiting.
The tarp was pitched too close, it would have been even less condensation if ventilation would have been better. I'm thinking to test a extra ridge line for support, not from tree-to-tree but between supporting ropes. I do not know it that will help but I will test it.
I left all the sleeping gear inside hammock. The next test should be about how soon (and if) the system looses it's warmth because of the condensation.
After few weeks I will test how to pack hammock with all the gear inside to my pulk.
My hammock has been hanging in my garden about two months now always ready for use. If one would do that with tent it would have rotten to the ground after few weeks.