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Heaters can we use snow?

Posted: Mon Dec 22, 2008 12:42 am
by honey
Wanted to know if the heaters that are in the tan mre bags can be activated with snow?

Thought of sending some of our MRE meals with son inlaw while snow mobiling here in Colorado.

Do the MRE meals freeze and make it harder to heat them ?

Re: Heaters can we use snow?

Posted: Mon Dec 22, 2008 1:03 am
by kman
Welcome to the forums, honey. That's a pretty good question about the snow. If only we had some snow around here, I'd go outside and try it myself right now...but alas, it was 60 degrees today so I can't help with a live demonstration.

I'm guessing that snow would work but you'd have to pack a lot of snow in the heater seeing as snow takes up to 10x the volume of water.

As for MREs freezing, they do freeze and if they get cold enough, it might actually take two heaters to get them warm enough. Depending on how much equipment you might be bringing, you want to bring a small stove and heat up a pot of water. You could put the MRE entree in the water to heat it up and then use the water for drinking afterwards.

Re: Heaters can we use snow?

Posted: Mon Dec 22, 2008 3:02 pm
by dirtbag
Hi, Welcome !
There has to be some liquid for the FRH to start up.
Mre's do freeze, and you'll have to use 2 in sequence, as they are designed to raise the temp only 100 degrees F. each.
What many do is to carry the MRE in an inside pochet, so body heat keeps it warm. Ditto a water bottle...
As mentioned, a small gasoline stove (not propane) is a wonder in cold weather, nothing like a hot meal and a drink.

Re: Heaters can we use snow?

Posted: Fri Jan 02, 2009 1:56 pm
by Imon
you can use snow or iced water too.
Last night, as I was outdoor, my little water bottle, which I used especially for the FRH, was frozen in the morning.
So I crushed the ice with my knife and filled some pieces of the crushed ice into the FRH.

It tooks more time to heat up the entree but it worked.
I think it took about 20 long minutes until the entree (sloppy joe filling) was hot enough to eat.

The best way is to have somethin liquid only in exceptional cases I would recommend ice or snow.


Imon

Re: Heaters can we use snow?

Posted: Sat Jan 03, 2009 2:38 am
by Treesuit
Well I guess if you have to use ice or snow to put in a FRH you might want to collect enough in a bottle and put it next to your body and let it sit or in your jacket. Seeing as how your body temperature will wam up the ice/snow and the meltwater will be enough to put inthe FRH. I've heard this done before if you need to drink some sort of potable water.

Re: Heaters can we use snow?

Posted: Sat Jan 03, 2009 2:19 pm
by Imon
Treesuit,belive me the bottle was very close to my body for a long time but it want not melt.
rather you will get frostbite.
your suggestion will not work if you have a temperature of -12°C/ 53,6°F or it would take longer then you use ice for the FRH.

Re: Heaters can we use snow?

Posted: Sat Jan 03, 2009 2:39 pm
by Big Galloot
You may wish to consider adding calcium chloride to water meant for use in your FRH. It can reduce the freezing point of water to -62 degrees Fahrenheit. Even table salt can reduce the freezing point in water to 2 degrees in a 20% solution.

Calcium chloride is safe to consume and used in foods to increase saltiness without increasing sodium content. Pickles and sports drinks are common uses.

Re: Heaters can we use snow?

Posted: Sat Jan 03, 2009 2:41 pm
by housil
Imon wrote: (...)
a temperature of -12°C/ 53,6°F
53°F = 11°C

-12°C = 10,4°F

:wink:

I have been on Reserve Winter Combat Trainingen at ~-13°C at US Radio Station Breitsohl

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We woke up in the morning with our water frozen inside then canteens. It was impossible to melt them with just our bodies "heat". We had to meld snow in the canteen cup on a tommy cooker for tea/coffee.

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"Occupied" barn :wink:

Re: Heaters can we use snow?

Posted: Sat Jan 03, 2009 3:02 pm
by Imon
housil thank you ! what a mistake :oops:
~-12°C are ~10,4°F,
with 53,6°F it will not be a problem to use the FRH, there is enough water in the nature :wink:
as it wasnt possible to work with open flame or fire to melt snow my two options were
1)use the ice of the bottle for the FRH
2)no warm food :(

so my decision was to try the first way...and I had warm food :)

Re: Heaters can we use snow?

Posted: Sun Jan 04, 2009 1:08 am
by dirtbag
Well, you can always use your "onboard" hot water..... :x
98.6 degree Fahrenheit = 37 degree Celsius
I guess it just depends on how hungry you are! :lol:
I think I'd try snow first, myself....... :mrgreen: