How much does a sleeping bag liner increase warmth?

[Rick.in.AZ]

the space blanket idea is interesting. I was planning to take one as a ground cloth anyway - to save the bottom of the tent. I have used these as ground cloths before - While it is imposible to get them back in the original package, with practice they will go in a sandwitch size zip lock bag.

Also, I did a bunch of googling this weekend - seems that on the backpacker side, most feel that silk liners are really only for keeping the bag clean - dont count on more than 2 or 3 degrees add.

Now the fleece liners seem to add more.

I am thinking I'll grab the phantom 45 and spends some nights on the balcony to see what additions I need.

[staehpj1]

Now the fleece liners seem to add more.

They also weigh a lot and do not pack very small.  To quantify that a bit, the Slumberjack Micro Fleece Mummy Liner weighs the same as the bag you are considering using a liner with (1 lb 1 oz).  I am not sure how small it packs, but I wouldn't be surprised if it was as big as the Phantom 45 you are considering using it with.  I think the Slumberjack is pretty typical of the fleece liners on the market.

If you think you need to go with a fleece liner I would advise using a heavier bag instead.  To my way of thinking the fleece liner just doesn't make sense at that weight and bulk.

[PeteJack]

one of those "emergency blankets" that fold up to wallet size

GOOD IDEA. Last May in Norway I camped overlooking the North Sea. I haven't been as cold in decades, my teeth were chattering. I carry one of those blankets with me for emergencies and never thought to use it (until now Aaargh) My frozen brain must have thought "Well, this isn't an emergency..." I envisioned using the blanket more as a first aid thing to help crash victims in shock. You live and learn.

[bogiesan]

I use a silk liner and it helps but what really saved me once when we encountered unexpected freezing conditions was one of those "emergency blankets" that fold up to wallet size and looks metallic.  I put it around my feet and pulled it up as far as it would go and then wrapped it under me.  It really kept in the warmth.  I always carry one and hope I won't need it because I hate being uncontrollably cold at night.

The noise of the metallic membranes can make you nuts unless you are in a real emergency. Reflective barriers are built into one of the Thermarest Neoair models. ON Ride Idaho 2012, two people were in troulbe because they had not bothered to set up and test their new Neoairs before the trip. They, and folks in the tents around them, discovered the noise was maddening.

All of these suggestions are worth epxloring. Just give yourself a chance to make good decisions by trying out the units in the stores and in your backyard.

[Rick.in.AZ]

Thanks all.  I was about to pull the triger on a phantom 45 and decide how much help it needed.  I found one on line for 220 or so.  But, it sees I waited tooooo long. Now everyone is back up to full list.  Worse, many places show out of stock.  Hmmmmm does that mean that Mountain Hardware is about to release a new model?  Eventhe phantom 32s are scarce.  That was another option - only 4 oz more.

I guess its a good thing I'm starting early with my plans........

Rick

[staehpj1]

Hmmmmm does that mean that Mountain Hardware is about to release a new model?  Eventhe phantom 32s are scarce.  That was another option - only 4 oz more.

Maybe a new model is coming or maybe the production run for the year has just run out early.  The phantom 32 is probably a much better option if you think that you might need a fleece liner with the 45.  Even a silk liner adds a bit more than that 4 ounces.

[Rick.in.AZ]

Well, the sale reappeared today, so I bit.   

Staehpj1-I decided your advice was good, and in looking at the numbers and realizing that the EN rating of my old bag is actually 17°, and that most the time I sleep a little colder than many people, I decided that yes the Phantom 32 was a better choice. So it looks like this decision is made now.

So I got the Big Agnes fly Creek UL 2 4 a tent, Nashbar waterproof front panniers to replace my worn-out REI rear panniers, a Phantom 32 as a lighter less overheating replacement for my marmot bag. Now I guess all I need is to replace my obsolete thermal arrest pad, find my old Trangia stove, and wait nine months to start.

Guess I'm getting anxious!

[staehpj1]

Well, the sale reappeared today, so I bit.   

I think you will be happy with the Phantom 32.