How do you prevent your drinking water from freezing?

Post climbing gear-related questions, offer advice. For classifieds, please use that forum.
no avatar
NiallK

 
Posts: 1
Joined: Tue Nov 05, 2019 1:20 pm
Thanked: 0 time in 0 post

How do you prevent your drinking water from freezing?

by NiallK » Tue Nov 05, 2019 1:42 pm

I was wondering how everyone prevents their drinking water from freezing while out in extremely cold conditions. I've read some methods online but wanted to know what peoples real experiences are with keeping their water warm.

For full disclosure I'm a design student with 4 years experience looking at creating a hydration product to be used specifically in below freezing conditions and would love to hear your thoughts!

User Avatar
ZeeJay
Forum Moderator
 
Posts: 246
Joined: Mon Jan 28, 2008 12:04 am
Thanked: 86 times in 61 posts

Re: How do you prevent your drinking water from freezing?

by ZeeJay » Tue Nov 05, 2019 2:06 pm

It depends upon how cold it is and how long you are going to be out there. For single day drips of length less than 8 hours and down to -20F, but warming to 0ish, starting with a nalgene of boiling water and using an old thick wool sock to insulate it is all you need and is relatively light weight. This assumes of course, that the bottle is in your pack and your pack is next to you and your pack is car temp to start with. For longer trips I also bring a thermos for the very end of the day.

User Avatar
Scott
Forum Moderator
 
Posts: 8546
Joined: Thu Aug 21, 2003 1:03 pm
Thanked: 1210 times in 648 posts

Re: How do you prevent your drinking water from freezing?

by Scott » Tue Nov 05, 2019 5:02 pm


User Avatar
ExcitableBoy

 
Posts: 3666
Joined: Wed Nov 09, 2005 9:33 am
Thanked: 663 times in 496 posts

Re: How do you prevent your drinking water from freezing?

by ExcitableBoy » Sat Nov 09, 2019 3:19 am

I use OR water bottle cozies. If you are considering designing something, I would think a cozy using 25mm Evazotte foam would be the ticket. For hydration bladders you could make an envelope and tube from 6mm neoprene.

Colin Haley used bubble wrap to keep his bladders from freezing during his one day solo ascent of the North Buttress of Mt. Begguya in Alaska, which worked for him.

User Avatar
nartreb

 
Posts: 2232
Joined: Sat Apr 03, 2004 10:45 pm
Thanked: 184 times in 155 posts

Re: How do you prevent your drinking water from freezing?

by nartreb » Thu Nov 14, 2019 8:41 pm

"Keeping it warm" and "keeping it from freezing" are two different things. Drinking barely-above-freezing water is awful.

In winter I'll carry two thermoses (REI type - you can pour without fully opening the screw cap) and I'll fill them with boiling water at the start of the day ( this means at home, if it's a day hike; at camp using a stove otherwise). When thirsty, I pour from a thermos into a cup ( thermos lid ) containing some snow. Adjust proportions as necessary so the water is a comfortable temperature for drinking. (Later in the day, as the water starts to cool, add less snow.)

A slim thermos will keep reasonably warm for around twelve hours unopened. If you're opening it once or twice an hour, it'll cool below body temperature within eight hours, but still resist freezing a few hours more. That's my recollection based on hikes in New England, temperatures in the teens F, thermoses kept in an outside backpack pocket.

The Thermos is a heck of a good invention. It's hard to improve on the insulating properties of a vacuum. The one improvement I can think of would be some kind of mechanism to minimize the cooling effect of the air that you have to let in as the water pours out. You'd have a downspout for the water to exit, and an air hole to replace the water volume poured out, but the air hole would lead to a separate chamber from the water, with an insulated membrane between the chambers. (In effect, the water chamber would be in a piston.) Building that kind of mechanism (cheaply) inside a vacuum thermos is a challenge left for the reader :)

Design students looking at this kind of problem (insulated coffee mugs are the typical example - very big market there) are always tempted by materials that change phase. In principle, you can store a lot more energy by melting something (wax is a good one - works at the temperatures you're interested in, isn't toxic...) than just by heating something up. In practice, the space and weight needed by your heat-storage element usually doesn't make a lot of sense in comparison to the amount of water you're trying to keep warm.

User Avatar
nartreb

 
Posts: 2232
Joined: Sat Apr 03, 2004 10:45 pm
Thanked: 184 times in 155 posts

Re: How do you prevent your drinking water from freezing?

by nartreb » Fri Nov 15, 2019 1:03 pm

PS I haven't made the switch yet, but hydration bladders with bite valves are clearly gaining market share, starting with the military. I believe the state of the art for winter use is to blow air into the tube (against the weight of your pack!) after each use, clearing the tube of water so it doesn't freeze shut. There's got to be a way to improve on that.

User Avatar
ExcitableBoy

 
Posts: 3666
Joined: Wed Nov 09, 2005 9:33 am
Thanked: 663 times in 496 posts

Re: How do you prevent your drinking water from freezing?

by ExcitableBoy » Fri Nov 15, 2019 4:05 pm

6mm neoprene sleeve that the bladder slides into with a neoprene tube for the hose.

User Avatar
Grampahawk

 
Posts: 540
Joined: Sat Jan 27, 2007 4:42 pm
Thanked: 8 times in 5 posts

Re: How do you prevent your drinking water from freezing?

by Grampahawk » Fri Mar 20, 2020 8:23 pm

The "start with hot water/thermos" idea posted by Nartreb is the best idea if it's going to be below about 15, or windy. I also use the Outdoor Research water bottle coozie. I like how I can hang it from my pack for easy access. I have experimented with placing some chemical toe warmers inside the coozie but I can't tell if they really work very well.

User Avatar
nartreb

 
Posts: 2232
Joined: Sat Apr 03, 2004 10:45 pm
Thanked: 184 times in 155 posts

Re: How do you prevent your drinking water from freezing?

by nartreb » Fri Apr 03, 2020 9:29 am

Ah, why didn't I think of this:

portable radio-thermal generator

https://www.smbc-comics.com/comic/pu

The following user would like to thank nartreb for this post
Stu Brandel


Return to Gear

 


  • Related topics
    Replies
    Views
    Last post

Who is online

Users browsing this forum: No registered users and 0 guests