Science Lesson

By Kretzky Ranked #7 - Lightweight Sleep Pads September 30, 2009

4 Stars cause it costs more than spending a night in a 4 star hotel.

With that said, I love this thing. Definitely the most comfortable I have been sleeping outside. I didn't slide around on it at all, in fact it made rolling around in my sleeping bag a little more challenging. I had no issues with being cold down to 35 deg. I haven't gone colder than that with it yet, not sure I'd' want to go too much cooler without adding something else underneath.

Blowing it up isn't too bad. There is one thing to be aware of though, some people have complained that this thing leaks, or deflates on its own. This is wrong, to debunk this - little science lesson coming up... PV=nRT (That's pressure x Volume = moles x constant R x Temperature)
Don't worry about n & R they're constants. So Basically Pressure x Volume = Temperature. What that also means is that PV/T = PV/T in the same closed container at two different temperatures, obviously. So basically, what I'm getting at is the air you're putting into this thing is 98 degrees. Let it sit out at camp for a while before you go to bed and it's going to cool off. Pressure inside isn't going to change, but you better believe the filled volume is. Based on the geometry of this thing, it's about 3000 cu in. So if you fill it up with 98 degree air, and then let it cool to say, 60 degrees, it's only going to be about 1800 cu inches - yeah, it'll look like it lost 40% of its air!

Some of you may have followed that, some people’s eyes may have glossed over reading it, but if it made sense to 1 person I'm happy. Hope it helps.
All in all this thing is awesome and I recommend it if you can afford to spend all that money on it. You just might have to top it off with a little more air before you go to bed.

View Details: Therm-a-Rest Neoair Sleeping Pad

Helpful Votes: 4 Yes | 0 No