Originally Posted by patermagnus
I have been lurking on this thread as I recently purchased a Downmat 7 LW. I have to go to ground frequently (Cub Scouts). It is fantastic in a tent. I was hoping that I could use it in my hammock as well.
This weekend had a chance: Down to 32 F. I inflated the mat so that there was air distributed throughout and shook it to loft the down. I'll estimate that it was 70% filled. It was still very mobile. I layed on it for about 10 minutes during the day just to see if it would work. I then went to bed at 11 PM. Was wonderful until about 2:30 AM. At that time I was awakend by cold spots in whatever spot had the most pressure. My guess is that the air had a chance to work it's way to be more toward the feet. I still could feel some air when I reached between the layers of my WBBB. I tried to gt back to sleep, but I dont tolerate cold spots as well as I want. Got up and put on my DIY insultex. that was much better.
If anyone has any other ideas, I am all ears. I would like the option of going to ground if needed.
As warm as it's been during the day, up in the 50-60's this past weekend, then getting to freezing at night. I'd be willing to bet you had some deflation as the air inside the mat cooled. I think if you'd have put some more air in it you'd have been back to where you first were.
The same principle with your tarp. If you set it up in 70* nice and taught and come back at midnight and it's 32* you're going to notice a lot of sag and nothing has changed but the temp.
Also, and I really think this helped b/c I think the real trick with pads is eliminating draft since it's a more rigid object, you may want to try zipping your rain shell or down jacket or whatever over the foot box. This helps trap that warm air so you're not just warm on the spots making contact. I noticed a big difference after doing this but dont' know if it's because of the replacement mat or the jacket, maybe a combo of both. But try it out.