Winter Program Trip Help

Ray Jardine's formula is 40 degree F per inch of loft

If you're okay at 18 F with quilt, and add 1/2 inch of loft with summer sleeping bag, you should be good down to 0 F. Presumably your summer bag is thicker than 1/2 inch so you should be good.

But that's a simplification, one person's formula, "your mileage may vary".

I would humbly suggest bringing the heavier bag, which should remove any doubt about your pad situation (I'm assuming you don't want to go out and buy another pad for this trip). If you haven't tested your insulation setup in your backyard and aren't certain that it will work for you at temps around zero, I don't think your program leader will be thrilled if you are cold at night. Sounds like your quilt setup might be enough warmth, but I can't give you a definitive "yes" on it. Someone else should be chiming in with CLO values and other figurings, but I'm not done with my coffee yet.

If it were me, I'd lighten up my other gear to carry less during the day but make sure that I'm sleeping just as warm as everyone else at night.

Where is your program taking place? Will you be working hard to get to camp? Sleeping at altitude? What kind of shelter?

Have fun out there.

Wow, thanks for quick replies. Sounds like the heavy bag is the safest bet (bummer). This trip is somewhere in the Adirondacks. We probably will not be working very hard during the trip, but I could be wrong about that. Max 5-6 miles/day through snow with snowshoes. No sleeping at altitude. I would like to cowboy camp/sleep in my bivy but we will also have tents. Im trying to lighten the bag load because I am still required to take a LOT of other stuff (40 oz. fuel, 1lb thermos, 7lb pack, plastic mountaineering boots which weigh a lot, really heavy tents). Im looking forward to it but its going to be a lot different than my personal trips!
Evan

"Is the z-rest + neoair combo going to be enough to inhibit conductive heat loss?"

A generalization is that the R-Value of ground insulation should equal top insulation.

You do the math…

Ok so I know that the R value of my system will be 4.5. What would that relate to on the top insulation? 4.5 inches of loft? If so this would bring me well below the -20 degrees F equated with 4 inches of loft on the backpackinglight chart. Looks like my neoair+z-lite system would work then!
Thanks
Evan

> I would like to cowboy camp/sleep in my bivy but we will also have tents. Im trying to lighten the bag load

Don't carry the bivy in addition to whatever tent part you have to hump. Going to be warmer in a tent with others, too.

> plastic mountaineering boots which weigh a lot

Can I ask what's on the agenda to justify these instead of a good pair of pac boots? You mentioned snowshoeing but mountaineering boots are overkill if that's the only thing you'll be doing.

I dont know why the program is having us wear the heavy plastic boots, I think it is crazy. I cannot think of any situation we will be doing (non-technical things at low altitude) that will require such boots. Alas I am only a trainee and not able to convince them otherwise. Many of the people in the program already think my UL philosophy is irresponsible. Still working on that :)
Evan

I am not too sure about the neoair. But, with the -20 bag it will be fine.
(I have had the neoair down to 10F, I don't think I would take it any lower without more than just a 3/4 pad. I also only had a 0F bag.)

This might help you shave off 1/2 lb.

http://www.backcountrygear.com/catalog/accessdetail.cfm/GG1170

If you have a spare blue pad laying around, or some Reflectix, you can make your own in a few minutes.

The outfitter that you're going with has a lot of heavy equipment that is rated to record low temps that will last through many seasons of hard use by inexperienced users. From their point of view they just want to keep you safe and make sure everyone has a good time. Enjoy getting out and use this trip as an experience to help you lighten up when you go alone or with a group of more like-minded individuals. After all you're not going too far each day…but if you're carrying that much the food better be great.