It’s one of the most basic and needed requirements for survival. We’re going to discuss how to keep water from freezing (for those who live/operate in cold climates.
We know that water freezes at 32 degrees. If you can stay out of the cold, your water won’t freeze! But sometimes we have to operate in temperatures that are less than 32 degrees.
Believe it or not, dehydration is just as much a challenge in the cold as it is in the hot! So, how do we keep our water supplies from freezing?
There are plenty of articles on the web that discuss how to keep your water tanks from freezing. Some of them suggest electric heaters to keep your tanks above 32 degrees. Others discuss using solar (glass/plastic) to surround your tanks to take advantage of “free” resources.
What we’re concerned about in this article is mobile storage of water. How do we keep the drinking water that you are storing for mobile use from freezing?
There are two basic ways to do this.
- The first is to change the properties of the water to lower the freezing point.
- The other is to “package” the water in such a way as to keep the water from freezing.
|Ingredient||Freezing Point F||Freezing Point C|
Here we can see that while sucrose (common table sugar) is good at lowering the temperature by approximately 2 degrees, both glucose and fructose (fruit sugar), do a much more adequate job at lowering the freezing point. For long term storage, sugar water potentially promotes the growth of harmful bacteria, so it’s not recommended.
Salt on the other hand does phenomenally better at lowering the freezing temperature by approximately 17 degrees. This property of salt is one of the reasons why snowy cold climates salt the roads so that the water doesn’t form ice at normal freezing temperatures (or melts ice at freezing temperatures). Obviously no one would want to drink something with 1 cup of salt in it.
In this case to depress the freezing point by the same amount sugar does we only require 2 Tablespoons of salt.
We’re not going to spend a lot of time on the science of why this happens, but it’s a function of the solids in the water. Oddly enough, dirty water has a similar effect as adding salt/sugars to the water. If you have filter systems that you use for your water before using, filtering it AFTER storage will reduce the freezing temperature.
There are lots of options for the packaging of your water stores.
Igloo type water coolers
Stanley type unbreakable thermos bottles
Camel Bak hydration systems
Plastic water bottles as they come from the store
Camel Bak type hydration systems
2 Quart Canteens with Pouch
Arctic Canteen with Pouch
1 Quart Canteens with Pouch
The results are listed below. We used regular tap water in a commercial freezer. We identify the Arctic Canteen as an option but didn’t test it because we don’t have one.
|Commercial stuff:||6 Hours||12 Hours||18 Hours||24 Hours||48 Hours|
|Igloo type water coolers||OK||OK||OK||OK||OK|
|Stanley type unbreakable thermos bottles||OK||OK||OK||OK||OK|
|Camel Bak hydration systems||OK||Slushy||Frozen Solid||Frozen Solid||Frozen Solid|
|Plastic Soda Bottles||Frozen Solid||Frozen Solid||Frozen Solid||Frozen Solid||Frozen Solid|
|Plastic water bottles as they come from the store||OK||Slushy||Semi Solid||Frozen Solid||Frozen Solid|
|Camel Bak type hydration systems||OK||Slushy||Frozen Solid||Frozen Solid||Frozen Solid|
|2 Quart Canteens with Pouch||OK||Slushy||Frozen Solid||Frozen Solid||Frozen Solid|
|Arctic Canteen with Pouch|
|1 Quart Canteens with Pouch||OK||Frozen Solid||Frozen Solid||Frozen Solid||Frozen Solid|
Analysis of preventing freezing:
The plastic soda bottles were the worst of the stuff we tested. They froze solid very quickly. Definitely nothing that would be good to recycle!
Anecdotal stories told us that the genuine Camel Baks were very good at keeping water from freezing. In reality, we saw no difference between the genuine ones and the military hydration systems as far as keeping the water from freezing.
We did one more test. Once our water is frozen solid, we wanted to know how long it took to thaw so that we could have some drinking water. We looked at partial and complete melt.
|Commercial stuff:||1 Hour or less||1 to 2 Hours||More than 2 Hours|
|Igloo type water coolers||Never Froze!||Never Froze!||Never Froze!|
|Stanley type unbreakable thermos bottles||Never Froze!||Never Froze!||Never Froze!|
|Camel Bak hydration systems||Frozen Solid||Some Water||Completely thawed|
|Plastic Soda Bottles||Some Water||Same Water||Drinking Water!|
|Plastic water bottles as they come from the store||Frozen Solid||Frozen Solid||Some Water|
|Camel Bak type hydration systems||Frozen Solid||Some Water||Completely thawed|
|2 Quart Canteens with Pouch||Some Water||Slushy||Slushy|
|Arctic Canteen with Pouch|
|1 Quart Canteens with Pouch||Completely thawed|
Analysis of thawing (getting it back to water!):
Fastest thawing (less than one hour at room temperature):
One Quart Canteen taken out of the pouch. Definitely the best and fastest. Complete thaw in less than an hour!
Soda Bottle (thawed to create some drinking water, but not completely)
Two Quart Canteen taken out of the pouch (thawed to create some drinking water, but not completely)
Slowest thawing (more than two hours at room temperature):
Camel Baks (genuine and military) stayed as solid ice for over an hour. We got drinking water out of them at 80 minutes. The genuine Camel Bak was completely thawed in two hours. The military version still had ice in it at two hours.
The plastic water bottles froze solid and took a long time to thaw to drink. There was drinking water at the two hour mark.
For bulk storage in a vehicle, the five gallon Igloo type water coolers give you your longest amount of time before the water freezes. Here it is at 48 hours, dispensing nice, cold water!
At 24 hours before freezing solid, you could keep it in your vehicle for a day before you had to bring it inside to get warm again. For our test, we kept the cooler in the freezer the entire time. In a vehicle where you ran heat while you were driving, the temperature may never be cold enough for a sustained period to freeze solid.
We used a five gallon cooler. Interestingly, at quantities of less than five gallons, it froze solid quicker than when it was full.
A slight tip on using the cooler. Make sure that the threads on the top of the cooler where you attach the lid are completely dry. Yes, the water comes out the spout when you pour it, but the lid will freeze to the cooler faster than the water will freeze!