Space blankets on sleeping pads to increase warmth

[darstog]

In the Patagucci ad where Cordes is "trying" to melt water with his lighter on Azeem ridge, I noticed that he had a space blanket of sorts taped to his pad. Would the extra weight (1.5oz or so) of taping half of a space blanket to the top of your pad be worth it? A hardman pad (Evazote), will reduce conductive heat loss, but won't (unless I'm mistaken) reflect any radiant heat loss. If you add a space blanket designed to reflect radiant heat loss back, how much warmer would your pad be? Some of you with experience in thermodynamics should be able to help, right?

[tomtom]

You're kidding, right?

[darstog]

No, as it's pissing rain on my local trail run right now, I'm actually choosing to waste my time by becoming more and more anal about gear. Sounds like more fun than running in the mud again.

[John Frieh]

I hear if you preheat your pad in addition to wrapping it with a space blanket the heat retention is much better.

 

Wearing a windshirt to bed also significantly helps

 

Edited February 2, 2006 by John Frieh

[darstog]

Sounds like a good idea. Is this your personal ad? I didn't see your height/weight/favorite color.

[MatthewS]

Just hope you don't have a partner when you try this one out! I'm just thinking of all that horrible noise everytime you turn on your side.

[crackers]

i'll ask him what he was thinking with that...

[John Frieh]

Sorry to spray on your thread Chris

 

I can't comment on the ad (I haven't seen it) but I will say 10 minutes after that photo was taken that blanket disintegrated from wind... it wasn't gale force winds up there but it was noticeable. I doubt whatever you saw was a space blanket (or it could have but he was using it as a blanket and not a pad wrap)... my guess would be it could have been HVAC tape... I have wrapped a few pieces of gear with that for heat retention.

[jerseyscum]

I once laid a space blanket over the frame of a very small tent before installing fly, a moderately cold night. It seemed to make the tent warmer, but I have no idea if it really did. I do believe that tents with flys are much warmer than single walled tents.

[marylou]

I do believe that tents with flys are much warmer than single walled tents.

 

You're darn right they are. I asked someone who knows about these things, and my suspicions were confirmed. The air space between the tent body and fly acts as an insulating layer, making a 2-wall warmer than a single wall. I tend to sleep a bit cold and can confirm this.

 

[/thread drift]

[RocNoggin]

I have heard that space blankets become absolutely worthless if they are wet. has anyone heard anything about this?

[catbirdseat]

Space blankets work by two mechanisms. First they are impervious and block the wind. Second they reflect infrared radiation. They have almost no insulating value. The mylar has little tendency to absorb water, but water vapor could condense as droplets on its surface. Water is a great absorber of infrared light, so it's conceivable that it's ability to reflect might be diminished by a condensed water layer.

[darstog]

So what, then, does Cordes have on his pad? It sounds like space blankets have little use in the climbing world. I've heard of other people relating John's experience with space blankets being ripped to shreds in the wind. What's this HVAC tape stuff?

[Dechristo]

aluminum foil w/adhesive, usually 1.5 to 2 inches wide.

[tomtom]

Also known as duct tape. (The good stuff.)

[fern]

HVAC tape is not duct tape. Duct tape is not for HVAC work.

 

http://www.lbl.gov/Science-Articles/Archive/duct-tape-HVAC.html

[Dru]

Don't vacuum your duck

[mattp]

The HVAC tape I've used has a much stronger adhesive then does duct tape and it comes with a peel-off waxy backing, but it is also less durable for wear and tear and doesn't stand up to abrasion or repeated folding very well - it isn't designed to be tough because heating ducts don't move around or get brushed up against a whole lot. I wouldn't expect it to hold up well if added to a foam pad.

[marylou]

aluminum foil w/adhesive, usually 1.5 to 2 inches wide.

 

You can often find this tape at Boeing Surplus. Pretty cheap there too. Store it in a plastic bag to keep the adhesive from drying out. Really useful stuff.

[jerseyscum]

In the late 1970s REI sold a sleeping bag that used aluminized, perforated shell material. Typical goofy idea from REI. I never heard any reports about its effectiveness.

[Jedi]

While building my house, I used a foil backed insulation foam product. I layed down on a piece one evening (in Feb) while taking a break and it felt warm very quickly. I could feel the heat being reflected back.

 

The nice thing about a ridgerest pad is that it has "grooves" for moisture to collect in. I think that keeps the insulation in your bag a little drier. If you have a an emergency blacket stretched across it, you not longer have that feature. If the blanket is adheared to the contours of the ridgerest, then it would help. But then you have the added weight of the glue (whatever it might be).

A good test would be to cover one half of the pad with the blanket and see if if that side feels warmer while you sleep.

 

I wonder if there is an aluminum based paint that would work. It would wear off on the high ridges but is would remain on the rest of the pad.

 

Yeah, it's not like redesigning cams but it an interesting concept.

[Dru]

uk special - space blanket bivisack

[wfinley]

RE: Uk special -- Check this page out: http://www.psychovertical.com/?bivibags

 

Not that I buy how great it is (people I know who bought these never took them out of their gear closet). I duct tape a regular old space blanket inside my helmet - that way it's always around.

 

The Blizzard Bag gets its own category here as there is nothing else on the market like it. When I first started writing for High I wrote about these bags just as they were coming on to the market, championing what I thought was a classic piece of British design. They aren't easily pigeonholed, being part bivvy bag, part sleeping bag and part survival bag, which I think has counted against them. At the time I thought that thousands of people out there would be looking for a product like this, but it seems so far only the specialist shops, instructors/guides and the emergency services have switched on to them (or even know they exist). So in order to do my bit for UK industry I'm going to write about the Blizzard Bag again (you may have noticed I've not covered the same topic twice so far).

 

Firstly the Blizzard Bag is not a glorified foil blanket or poly survival bag. It is a lightweight sleeping system for those of us who need the minimum to do the maximum (those in trouble, adventure racers and Alpinists). The bag is vacuum packed for storage (0.7 litres) and weighs in at only 330g, is 100% waterproof and windproof, yet provides the warmth of a regular two to three season sleeping bags and is tough and tear resistant. The unique material, developed over 15 years, is more than twice as warm as goose down, yet completely waterproof and windproof. The bag is made from multiple layers of heat reflective and waterproof polymer sheeting, which are interspersed with elastic filaments. This gives the bag a kind of corrugated loft (1cm to 2cm of dead air), with the elastication hugging the body so as to reduce convection to a minimum and aid heat reflection. The inside of the bag is perforated to reduce condensation, but I think any user would probably be fully kitted up inside (although some mountain marathon runners sleep inside the bags in just their thermals at +5°). One problem with the bags is that they are noisy and so I'd recommend earplugs if you know you're going to spent the night in one.

 

Once the bag has been used it requires a stuff sack to compress it down again (compresses down to the size of a small sleeping bag) and can be reused as much as you want. I've seen testimony from several users who've been forced to spend the night out through injury or bad timing, both in the UK and the Alps (winter and summer), all of who were surprised how comfortable the bag was, along with Alpinists who are now using the bags as a lightweight alternative to a bivvy/sleeping bag combo.

 

The Blizzard also comes in a two/three person tube bag (530g/£27), which I think would make a great mountain marathon/emergency bag and they even make a jacket out of the stuff, which although looking a bit 'Doctor Who' could be a real winner for guides and instructors.

[pdk]

Putting a space blanket on the floor INSIDE your tent will also improve the heat retention of the tent. Works well for really cold winter stuff.

[crackers]

It turns out that the ground pad in question is not kelly's, it's josh wharton's. It had one side that was aluminized.

 

Kelly said he didn't know if it really helped or not, but they figured why not. He also doesn't know where Josh got it.

 

I'll go ask the manufacturer that I get my evazote from...