help me undrstand the need...

[W8lkinUSA]

Here's an interesting discussion based on skimming the first two posts. Hope you didn't sleep through your math classes..

https://backpackinglight.com/forums/topic/33188/

[Calait]

Here's an interesting discussion based on skimming the first two posts. Hope you didn't sleep through your math classes..

https://backpackinglight.com/forums/topic/33188/

Did not sleep through math class, however these formulas talked me into a square corner while looking at a circle.

[W8lkinUSA]

Yes. A calculator and the manufacturer's website is all you need.

The difference in down-filled ounce between the 20°F and 0°F. Divide that by 4. That's approximately how many ounces are needed for each 5°F.

Use this math, along with quilt's total square footage to determine decimal ounce per sqft required. (divide by 20 instead of 4; that's how many decimal ounces are needed for 1°F based on total sqft of manufacturer's quilt)

Here's an interesting discussion based on skimming the first two posts. Hope you didn't sleep through your math classes..

https://backpackinglight.com/forums/topic/33188/

Use this math to convert the temperature.

Perform first math calculation to the converted numbers. Knowing the figures for the first math allows for +/-temperate adjustments.

If original and converted numbers provided analogous results, then you're in the right direction.

Did not sleep through math class, however these formulas talked me into a square corner while looking at a circle.

Combine both calculations for your needs.

Err on the side of caution and go 5-10°F warmer, or start a thread in BPL forum for agreement on your calculation since BPL seems more detailed in that respect.

The math part sounds fun. The DIY, not so much...


I can double check your math if you want. I just lack experience in this DIY and its field test.. You should start a new thread if that's the case.

[XJ35S]

Um, No. Use this.

https://docs.google.com/spreadsheets...9HgnkJLAE/edit

[Irregularpulse]

This $12 sleeping pad and my Kelty Cosmic 20° has taken me down to 25° and I've stayed toasty. Now, I also had a light packable down jacket on and a proper base layer, but it worked. I've been lucky with condensation I guess. I pull the whole bag over my head when it's that cold and haven't woken up wet yet.

That said, an underquilt is 100% on my list. The pad is pretty annoying, but $12 vs $100+ when just starting out and buying everything else...

[W8lkinUSA]

Um, No. Use this.

https://docs.google.com/spreadsheets...9HgnkJLAE/edit

Nice! Why didn't I think of this formula? :-P

[XJ35S]

This $12 sleeping pad and my Kelty Cosmic 20° has taken me down to 25° and I've stayed toasty. Now, I also had a light packable down jacket on and a proper base layer, but it worked. I've been lucky with condensation I guess. I pull the whole bag over my head when it's that cold and haven't woken up wet yet.

That said, an underquilt is 100% on my list. The pad is pretty annoying, but $12 vs $100+ when just starting out and buying everything else...

Great point. I picked up two yoga mats that size at 5 below. Yup,$5 each and my wife won't hang, gets real dizzy easily. Thinking a 2"x2" zig zag and duct taping the two together and maybe a fleece with elastic straps sewn to one edge. That would be good for a few nights right now down in the 30's.

I'm working on an UQ DIY with milkweed ovum. I collected about 30 lbs of ovum and it's near equivalent to down.

https://www.hammockforums.net/forum/...JACKET-MITTENS