Frozen Water Supply

[LonghunterCO]

Wide mouth Nalgene water bottle in an insulated carrier.

I used one while in the Corps in Norway, Canada, NY, MN etc for cold weather ops - in a ski mobile rifle company. It's the only water carrier I could rely upon. The mouth is wide enough to get a knife into to break up any ice that forms on top.

Not as handy as a Camel bak but reliable.

+1. I ran USGI canteens on the AT once...once. Narrow mouth froze solid. Went to Nalgene and OR insulated carrier and never looked back. I was told by an old hiker that if I set them upside down in the carrier that at the worst the water would freeze on the bottom (which is at the top) and you invert it back up and you will be able to drink what has not frozen. I have not tried it (he could have been pull'n my leg.

Does anyone make a carrier that is a little more tactical/low key than the OR ones?

[UVvis]

I would disagree. Cold water is denser than warmer water; it falls to the bottom. The bottom and sides of a container filled with water freeze first due to convection. I have seen this many times on serious hikes in cold weather.

I respect Combat and if he has seen otherwise I would consider his opinion but it doesn't fit with physics or what I have observed numerous times. Maybe there is something I'm missing.

A little research will illustrate my point.

Not that I'm trying to call you on this, but...

Ice is less dense than water and floats. As soon as those crystals start forming, they float to the top.

Water is most dense around 4 degrees C, as it gets colder, it starts expanding again until it goes through a phase change and turns to ice.

Water is pretty good conductor of heat. For a container that we carry and drink from, the temperature is going to be pretty much constant through the body of water.

From my experience of working and living in the cold, containers do freeze from the top down. There is also a 'slosh' factor at play as well. The water sloshes around in a nalgene and freezes against the colder sides, helping the water freeze from the top.

The exception to this is with metal containers that transfer heat better than water. The water starts freezing to the sides and bottom and the crystals form against the container, so they don't get to float and freeze the water from the top down.

Ponds, rivers, and the ocean freeze from the top down.

[bkb0000]

ice cubes freeze from the top down.

i think exposed bodies of water freeze from the top down because the top is the part thats exposed to the cold air. naturally the ground or whatever insulator contains the water will not cool as fast as the air, or the water.

[UVvis]

Does anyone make a carrier that is a little more tactical/low key than the OR ones?

Maxpedition makes a mini rollypoly dump pouch that is just about the right size for a 1 liter nalgene bottle. It also has enough room to drop a handwarmer in it as well, but is not insulated. I'm partial to the black ones to take advantage of solar warming of your water.

[6933]

Just my .02 on last post based on my personal observations. Possibly several variables to consider that are particular to specific situations. I still say water freezes from bottom and sides first based on personal experience, physics experiments in college, convection, and thermodynamics. Ice cubes freeze at the bottom and sides first, with top coming last. We just see the top freeze. Bust open a freezing cube/bottle, etc., and one will see the bottom frozen also.

bkb- May be moving to your general area. If so, I look forward to getting together for some training.

Uvis- We aren't discussing ponds, lakes, etc. Your example is moot. We are discussing a container.

[UVvis]

Just my .02 on last post based on my personal observations. Possibly several variables to consider that are particular to specific situations. I still say water freezes from bottom and sides first based on personal experience, physics experiments in college, convection, and thermodynamics. Ice cubes freeze at the bottom and sides first, with top coming last. We just see the top freeze. Bust open a freezing cube/bottle, etc., and one will see the bottom frozen also.

bkb- May be moving to your general area. If so, I look forward to getting together for some training.

Uvis- We aren't discussing ponds, lakes, etc. Your example is moot. We are discussing a container.

Then we disagree. A pond, lake, or mud puddle is a container. They freeze from the top down. They also display insulated sides. According to convection and your statement that cold water is heavier, which is only true to four degree above freezing, then why wouldn't a mud puddle freeze bottom up, instead of top down? Wouldn't the sinking cold water from the surface be replaced by warmer water from the lower levels?

Please tell me what experiments involving thermodynamics, and convection had water freezing from the sides/bottom first so I can replicate it. If you were rapidly superchilling a container with a massive temperature differential, then you can do it. A slow freeze around zero C, water will freeze from the top down. I'm just saying that the available science doesn't support your claim.

Here are two pictures of a beaker (1L) of deionized water that started at 16.5°C. It was placed into a room at -5°C, for a period of four hours, thirty three minutes as of picture time.





Notes:
1. I broke another beaker but I needed to see in. Polycarb is next, maybe.
2. The second photo shows some cool wavy patterns on the bottom of the beaker. This is from the beaker sitting on a metal grate (removed for pictures), and the conduction through the glass gave the ice a formation site on the bottom of the beaker. It appears ice can form bottom up if you increase your cooling rate to the bottom of the beaker compared to the rest of the container.
3. The center of the beaker is still liquid
4. The sides and bottom have a very slight film of crystal grown on the beaker.
5. Bulk of ice present is forming from the top.
6. The beaker was held static, there should have been virtually no fluid movement.
7. Despite the flash, note the cool crystals forming off the base of the ice slug at the top of the beaker.
8. I'm a nerd

Aside from the forced conduction based cooling at the base forming crystals, and this being a non-scientific study... my observation is that ice is forming at the top and working it's way down.

[6933]

Uvis- My "experiments" have been when out hiking in cold weather. Could be due to the sloshing, etc., don't know. The lab and real world don't always go hand in hand. By the way, I'm quite at home in the lab as well. College physics, Pchem, Org. Chem., Analytical Chem, etc.

Why would a lake freeze from the top down? Because it's sitting on a heater called the ground. Going to hang a glass in the freezer and see what happens. Will report back findings.

Thanks as*****. Thought I had left the nerd days behind.

[Gutshot John]

Because it's sitting on a heater called the ground.

I'm afraid that's not really correct. Conduction by contact with the ground pulls heat away from a body of water faster than the air. This is why you put a pad down to sleep on ground.

I'm not even a physics major but from what I can tell there is actually some abuse of terminology here.

Convection occurs as a transfer of the warmed matter (i.e. steam or the rising and falling of cold/hot water within a body).

Conduction is through direct contact with an object (i.e. sit on a cold stone and see whether your ass or your face gets colder faster).

Radiation is transferring energy by waves (i.e. into the air).

IIRC my environmental medicine training said that conduction results in the fastest cooling, convection is the second fastest and radiation is the slowest.

[6933]

GS- The ground can't pull away heat to a level below the temp. of itself. Ground is usually approx. 50-55F. You put a pad beneath you b/c your body is much warmer and the ground pulls away heat. If your body were 50-55F, the ground would pull no heat. The conduction is from the ground to the water, not the water to the ground.

Uvis- Possible flaw with the beaker exp. The beaker base starts at a higher temp. when compared with the ambient air temp. in the freezer. The bottom of the beaker would be "heated" in comparison to the top of the water which is exposed to the air.

I took a regular drinking glass and left it in the freezer for two hours. My thinking is that the glass bottom and sides would be at the same temp. as the freezer air. Pulled glass out quickly and filled half full with tap water. The freezing temp. will be affected by particulates but the effects should not be important for the discussion. Checked back in 30 min. to find ice on top. Broke ice, poured out water, found layer of ice on bottom. To really be proper, it would require a set of glasses in protected environment, with a glass being removed(rest left in) and checked for ice formation on a set time table. I'm going with ice forming on the bottom simply because cold water is denser, would sink, and freeze on the bottom first. If we can design an experiment that is repeatable by both, I'll be glad to admit I was wrong, or, to toot my own horn.

[UVvis]

GS- The ground can't pull away heat to a level below the temp. of itself. Ground is usually approx. 50-55F. You put a pad beneath you b/c your body is much warmer and the ground pulls away heat. If your body were 50-55F, the ground would pull no heat. The conduction is from the ground to the water, not the water to the ground.

Depends on where you are. I'm in a permafrost area that starts a couple inches down. Water here that forms heats the ground, and it still freezes top down.

Uvis- Possible flaw with the beaker exp. The beaker base starts at a higher temp. when compared with the ambient air temp. in the freezer. The bottom of the beaker would be "heated" in comparison to the top of the water which is exposed to the air.

The beaker is starting at water temperature. Did you notice the small amounts of ice forming to the bottom of the beaker? This is because the beaker (conductive glass) was sitting on a large metal (again, temp conductive base). The metal base was cooling the beaker from the bottom, and why we got ice forming there. The beaker was being cooled from the bottom while the water water was heating the beaker. This is why I had a very thin film of ice forming against the side, but why the ice crystals were not propagating from the sides/bottom point, and rather growing from the top of the ice layer.

I took a regular drinking glass and left it in the freezer for two hours. My thinking is that the glass bottom and sides would be at the same temp. as the freezer air. Pulled glass out quickly and filled half full with tap water. The freezing temp. will be affected by particulates but the effects should not be important for the discussion. Checked back in 30 min. to find ice on top. Broke ice, poured out water, found layer of ice on bottom. To really be proper, it would require a set of glasses in protected environment, with a glass being removed(rest left in) and checked for ice formation on a set time table.

So, you are making a frosted beer glass...

The problem here, is that if I'm using a 'heated' glass, you are using a chilled glass. If the thermal mass and temperature of your glass is that cold, of course you are going to form ice on the sides/bottom, as you are super cooling those regions ahead of time, and exposing the water to an area that can loose heat to the container faster. You just demonstrated that water will freeze against a cold object. I tried to demonstrate a body of water slowly being cooled along with it's container

From my beaker, the thin film of ice against the sides/bottom indicate that the sides/bottom were below water freezing point, it was being cooled from the sides/bottom by glass. My water had more thermal mass, but this shows evidence that the glass was cooling the water inside.

I'm going with ice forming on the bottom simply because cold water is denser, would sink, and freeze on the bottom first. If we can design an experiment that is repeatable by both, I'll be glad to admit I was wrong, or, to toot my own horn.

Not to nitpick, but check your physics/chemistry, as the part in red is simply not correct. Water is most dense at about 4°C. As it continues to cool to 0°C, the density becomes less. Check wiki here

Water at 0.1°C is less dense than water at 4°C, and the colder water would rise to the top, except that they have a habit of mixing and sharing heat pretty well.


My experiment took a container and water at close to thermal equilibrium and chilled them.

Your experiment poured water into a sub freezing temperature container.

Which more accurately reflects taking a water bottle for a hike?

How about this? I get the thinnest poly/lexan bottle I can find, fill with DI water, and put it into a polystyrene foam insulated container, which will go into a -5° or -10° chamber. Check every hour as I remember to see the status. This would give us a relatively insulated chamber being cooled as slowly as possible, giving the water, bottle, and insulation the maximum time to come to thermal equilibrium and slowest chill possible. Hopefully, this would let the water react independently of a 'heated' container, or your super cooled container, as the water should be the last item to cool.



Either way, I'll buy the beer after we go shooting sometime.