Originally Posted by
Time Zone
Just did some backyard testing, and found that wearing fleece PJs instead of thin long underwear makes a huge difference for me. A second ridgerest CCF pad may have helped too, but I've done that before and not noticed much difference (in warmth ... or cushion, ha ha). A tale of two nights:
40F overnight low. 1P tent (hybrid single/double wall), RR Solar (R 3.5), synthetic mummy EN comfort = 14F, Duofold thermals (poly inner, poly/merino outer). Was just adequate/cool ... not cold, but not warm enough to sleep soundly.
27F overnight low. Same tent, same bag. Added RR Classic (R 2.6) under RR Solar. Wore fleece PJ pants, fleece 1/4 zip pullover, instead of duofolds. Was TOASTY and slept soundly.
If I had a WM or FF bag of the SAME rating instead, could I have been toasty with just the duofolds? Possibly. But would that be because they rate conservatively? If not, what would it be? I don't doubt such a bag would be smaller and lighter for a given temperature rating. But if you are new to winter camping and aren't sure it's for you, what's the problem if you aren't ready to buy the very best bag possible? If your kid wants to learn guitar, do you buy them a Martin or Gibson right away? What's wrong with starting on a Yamaha?
Those interested in the relative effects of pad thickness and clothing worn on the insulation value of a sleep system (bag, pad, clothing) may enjoy reading the paper given by KSU's McCullough, Issues Concerning the EN 13537 Sleeping Bag Standard (presented 6/22/09). Interesting quote: