Emergency rations for storage in a car?

Posted by: James_Van_Artsdalen

Emergency rations for storage in a car? - 08/23/09 02:00 AM

I'd like to store some emergency rations & water - something like the Datrex stuff - in my car, but the temperature extremes seem problematic. Has anyone found rations & water rated for temperatures found in a car? I'm thinking of heat degrading the food & repeated freezing rupturing the water storage.

The motive for this thinking: I have 30 days of rations at home that can be quickly put in the car for an emergency evac or whatever. But I spend a lot of each week not at home and there's a good chance the call to run will come while away from home, possibly with no way to stop by home before heading for the hills. I already keep a "toolbox" crate in the car of everything I might need during evac & at civilized shelter, except the big ones: food & water.

My Honda Odyssey has large door pockets and there's room amongst other supplies for a couple of day's food & water there, and another week or two in the back.
Posted by: scafool

Re: Emergency rations for storage in a car? - 08/23/09 02:15 AM

I have never had problems with plastic water bottles freezing and bursting. I have not had problems with tinned food bursting the cans either, though some of them did bulge a bit at the ends.

I found most chocolate bars melted and got a white bloom on them from the summer heat, but they were still perfectly edible.

The cold part is Canada. I am not sure if it gets as hot inside my car in the summer as yours might get. I do know it gets hot enough to melt plastic things if you leave them on the dash.
Posted by: MDinana

Re: Emergency rations for storage in a car? - 08/23/09 03:00 AM

I have some of the aluminum water packs in my car. No problem after 2 winters in Detroit. As for food, my MRE is still edible after a few years in the car (Missouri and Michigan weather). I wouldn't leave them more than a few years though. Other options include granola/power bars, Datrex or Mainstay bars, the aluminized-packs of meats found in the grocery store. Again, I've tried all these after months to years, and never really had a problem.
Posted by: timo

Re: Emergency rations for storage in a car? - 08/23/09 05:05 AM

Aqua blox for water.
Mainstay food cookie rations for food.

Both tout a "5 year shelf life" so I would expect them to last maybe 3 years in a car
before I'd even begin to worry.

You could also get a Scepter Runt 2.5 gallon water can.
Tough enough for our military.

The mainstay cookie rations taste pretty darn good too.
Posted by: Tjin

Re: Emergency rations for storage in a car? - 08/23/09 05:10 AM

You could put the ration in a good cooler to stabalize the temperature during the day.
Posted by: LED

Re: Emergency rations for storage in a car? - 08/23/09 07:59 AM

1. Replace the food often (once every 6 months)
2. Park in the shade as much as possible
3. Hope you never have to eat your car kit food laugh

Thats what I do anyway. I also keep some dog food in the car but I swap that out every month or so cause it just doesn't store well. Anyone know if freeze dried meals would do better in volatile storage than MRE's (taste wise) due to the water content?
Posted by: James_Van_Artsdalen

Re: Emergency rations for storage in a car? - 08/23/09 11:33 AM

Datrex doesn't list storage temperature ratings but Mainstay does.

From the Survivor Industries web site the Mainstay food storage temperature range is -40F to +300F and for water packets it's -40F to +210F. The shelf life for both is five years.

That fits the bill. Datrex is also rated at five years though they don't list the storage temperatures.

Thermal cycling, or repeated freezing & thawing, is pretty tough on most materials when water is involved and can lead to microfractures, or empty water containers when you need them most.

Water can: the water packets are going to have a much longer shelf life than anything I can do at home with a water can. Also, small water packets are easier to put in several places around the car than a big water can (one water can in the car would be like all-eggs-one-basket but I'll put several water packets in many different places in the car).

I definitely hope to never eat that stuff except for the test run! The food I only plan to eat when the alternative of not eating it is even worse...
Posted by: Jeff_M

Re: Emergency rations for storage in a car? - 08/23/09 01:17 PM


The climatic and storage conditions on most commercial or recreational life raft packs are more extreme than those in a car trunk in a southern summer or northern winter.

I've looked into this issue. My conclusions were that "lifeboat rations" are the only foods I'd rely on for several years. So they are my core food supply. Dissappountingly, the packaging doesn't seem to hold up all that well to a lot of movement, vibration or handling, so mine got an extra layer of aluminum foil and a vacuum pack.

There are lots of supposed "official" MREs out there, of varying quality. I conservatively count them as done after a year, or one full season of high temperature trunk storage. I usually have only one or two in there. I also have a small amount of COTS (commercial off the shelf) food items in my pack. My experience with long distance backpacking has taught me that, ounce for ounce, peanut butter is a good choice; it will keep you going a very long way. Likewise, my work in disaster zones has shown me the value of a little electrolyte drink mix for working in hot environments. The COTS stuff also get tossed each winter.

I carry 3 liters of water and ice in an insulted Camelbak that gets replaced every third day, a liter in a Nalgene bottle in an outer pocket of the BOB that routinely gets dumped and replaced whenever I think of it, and several commercial water bottles for general use, along with another empty 3L water bladder in the BOB itself.
Posted by: Susan

Re: Emergency rations for storage in a car? - 08/24/09 12:26 AM

It occurred to me that having some kind of insulated container with one of those minimum/maximum thermometers in it could give a reasonable idea what the temperatures inside a container would be during temperature extremes for your own local areas. I don't have that kind of thermometer, so I've never tried it.

Has anyone else?
Posted by: Compugeek

Re: Emergency rations for storage in a car? - 08/24/09 01:09 AM

Such timing. I just set up this exact experiment yesterday. I'll be able to monitor both inside the trunk and inside the cooler. If no one else has data, I'll post my results next weekend.

There's no shade where I park at work, but plenty of asphalt. This should be a pretty good test.
Posted by: oldsoldier

Re: Emergency rations for storage in a car? - 08/24/09 12:03 PM

Geek, I am certainly interested in your data. I drive a jeep, and the temps are pretty extreme. Any food storage for me within the jeep is limited by the space allowed-the temps can get HOT inside the cab, as the only thing between the sun & the inside is a thin layer of vinyl/canvas. Or, if the top is off-exposed directly to the sun. Either way, they are exposed to fairly significant extremes, and data like this would be valuable to me. Thanks in advance for this!
Posted by: Compugeek

Re: Emergency rations for storage in a car? - 08/24/09 12:53 PM

Will do, then. Although I can't provide exact air temps from work (that thermometer failed, and hasn't been replaced yet), the forecast for the area is high 80s to low 90s (F) all week.
Posted by: Dan_McI

Re: Emergency rations for storage in a car? - 08/24/09 01:45 PM

As stated by Jeff M, lifeboat rations should be fine, and there should not be many other types of food that will last better. When you consider that these rations are designed to be stuck into a compartment on a lifeboat, for a few years, they will hold up to what happens in your car. A lifeboat is going to be as exposed to elements as you car, but the elements are probably going to worse for the lifeboat's environment.
Posted by: AROTC

Re: Emergency rations for storage in a car? - 08/24/09 09:49 PM

I'd like to start out by saying I don't have any credentials in this area, I'm not a long distance backpacker, professional chef, nutritionist or anything else. I am however a decent cook and I've been pondering the idea of survival cooking and eating for a long time. Just search my name and cooking on the forums and you'll see its a pet topic of mine. I also just bought the book NOLS Cookery and started looking at food to take camping (I just returned to the US from Korea and plan to go camping now that I'm back).

I will assert that while not eating for a week won't kill you, it might contribute to getting you killed. Food gives you energy to keep you warm, it fuels physical activity and both fuels mental activity and calms you down so you don't do something stupid. I will also assert that the better the food you carry is, the better you perform.

So first off, for long trips, over about three days, NOLS recommends a weight based bulk rationing, rather than planning individual meals. That means you take so many pounds of quick bread mix, so many pounds of soups and sauces, so many pounds of pasta and so on per person per day. The goal is to give you enough nutrition for a long trip, but also to give you the option of deciding what you want to eat on the day you eat it, not two weeks in advance. I think this is great for backpacking, but I would modify it for survival by including more ready to eat foods. Ready to eat foods are for the first day or two and for times when cooking isn't an option.

Along with that, came the realization that the super market is packed with foods you can "cook" just by adding water and heating. I knew this already, but since I don't normally eat those kinds of foods I wasn't really that familiar with them. You can get brownie mix, mashed potatoes, chedder broccoli soup, alfredo sauce and on and on in a box, and they all are just a couple cups of boiling water away from a "homecooked meal". Likewise, the supermarket is full of "MRE entrees". Soft retort or plastic pouches of foods identical to MRE's.

The final piece is because these things take so little to prepare, you can eat much better than MREs or Mainstay bars, for less money (spent on consumables), with just a camp stove and a few utinsels. A small pot/frying pan mess kit, a canister stove, a good water bladder, a tupper ware bowl, a small strainer and a spoon are about all you need plus or minus. You also need/want to carry a few consumable tools like cooking oil and a few condiments.

The down side is you do need to do some work, not just tear open and eat. This is also a plus because if you're waiting by your car for three days for help to arrive you have to do something to occupy the time. Also you need to do some practice and planning. You also need to carry a decent amount of water for cooking and cleaning. Finally, these foods are long shelf life, but not indefinite. Say six months in a shot, but probably safe for much longer. But since they're regular foods and inexpensive, rotating them out and eating them for lunch or dinner isn't much of a hardship.

In case you're wondering I've carried a butane/propane canister stove and lantern in my car both in Texas summer heat and Wyoming winter cold. I've never noticed any evidence of leakage or had any performance failures. My lantern and stove were both made by coleman and cost about $20 each (actually I bought them on sale, but they were supposed to be $20). My whole kitchen set probably cost over $100, but includes about ten mini-nalgene bottles for seasonings, a pepper grinder, a whisk, a strainer, a spatula, a fry pan and pot (I only carry one each from a nesting set), a tupperware bowl, an insulated mug, a folding chopstick and spoon set and is completely and totally over kill.

I recommend the book NOLS Cookery, they have a lot of experiance cooking and eating outdoors, and I highly recommend you take a walk through the grocery store reading the instructions on packaged foods. They were both eye openers for me.
Posted by: ironraven

Re: Emergency rations for storage in a car? - 08/24/09 10:59 PM

Data is a good thing. Absolutely share it.
Posted by: James_Van_Artsdalen

Re: Emergency rations for storage in a car? - 08/25/09 03:17 AM

My question was really aimed more at what to carry in situations when I *don't* think I'll need it ... but I'm wrong. What I might carry on a trip through the Nevada deserts is not the same as what I happen to have in the car on an ordinary visit to a friend's house a few miles in the country.

Space budgeting becomes an issue. I don't want to depend on something that has to come out of the car every time I need to fill the trunk with vacation luggage, shopping trip loot, etc!

And as I mentioned above I like the idea of smaller rations that can be spread around the car, just in case you can't get the trunk open after a crash.

It looks as though I should be able to get two day's food & water in the driver door's storage pockets, along with a PLB, CB radio, flashlight and escape tools: all within reach even if pinned in. Being able to get to the toy box in back almost becomes a bonus rather than a necessity in a lot of cases.

Both Datrex and Mainstay claim to meet some Coastguard standard. I hope to track that standard down at some point but I'm betting it means "lifeboat ration".
Posted by: scafool

Re: Emergency rations for storage in a car? - 08/25/09 03:47 AM

I keep some canned beans, canned peaches and canned sardines in the trunk of the car. I don't like them inside the car because I don't like things that can turn into missiles if I am in a crash.
Inside the cab I usually have a stash of chocolate bars and some hard candy.
My sister-in-law keeps a few bags of granola style trail mixes and dried fruit slices.

I like the canned stuff because iron rations are almost indestructible and come in many flavours. It helps to write what they are on the end of the can with marker just in case the labels come off.
Tinned food is pretty cheap too. Most of the time it does not even need heating, and it usually gets used and replaced frequently enough that expiry dates are not a problem.
The only special tools are a can opener and a table spoon.
Posted by: celler

Re: Emergency rations for storage in a car? - 08/25/09 11:19 AM

Originally Posted By: LED
<snip> Anyone know if freeze dried meals would do better in volatile storage than MRE's (taste wise) due to the water content?


I think this is a great question, but I do not have the answer. Mountain House Pro packs are widely available and the addition of a small camp stove like the JetBoil would add quite a bit of variety over Mainstay cookies. But how long are they going to last in a hot car trunk in the southeastern United States? The lack of water in the package would seem to indicate quite a while. Does anyone have any real life experience on this?

Craig.

[Post-edit]

From Mountain House's website:

Based on storage studies over several years, in 2006 the shelf life was increased by an impressive 40%, from 5 years to 7 years! That’s right -- our shelf life is at least 7 years from the date of manufacture as long as the pouch is stored unopened in a cool area. After 7 years a change in flavor and appearance may be noticed. For best results, avoid prolonged storage at temperatures above 75° F (24° C).
Posted by: AROTC

Re: Emergency rations for storage in a car? - 08/25/09 11:05 PM

Originally Posted By: James_Van_Artsdalen
My question was really aimed more at what to carry in situations when I *don't* think I'll need it ... but I'm wrong.


I got this, but you also mentioned a timeline of about seven days in your original post if I recall correctly. I still think you're probably better with off the shelf foods rather than the Datrex/Mainstay and just rotating every few months. A week of food, a couple days of water and a cook set should each be about the size of a loaf of bread. I think if you want a week of food, I think a modular system would work best. The first couple of days of food and water in ready to eat foods in arms reach of the driver. Pouch spagetti and trail mix stuff. Then a cook kit, dry goods food and more water split up somewhere in the rest of the car.
Posted by: Susan

Re: Emergency rations for storage in a car? - 08/26/09 03:11 AM

I was curious about the Mountain House foods in heat, so I contacted them.

Their response:

"The trunk can get pretty hot. Although it does cool down at night, I do think that the extreme heat in a trunk will effect the
flavor. Depending on just how hot it gets where you live, the flavor profile could change in just a matter of weeks if the temps are really hot.

"I am pretty confident that after an entire summer in the trunk, there would definitely be a difference in the flavor profile. Almost like a stale flavor.

Melanie"
Posted by: dweste

Re: Emergency rations for storage in a car? - 08/26/09 04:53 AM

Way to go to the horse's mouth!
Posted by: celler

Re: Emergency rations for storage in a car? - 08/26/09 10:21 AM

Sounds like Mountain House believes taste will be effected, but they did not say anything about heat making the food inedible. I will be very interested to see the results of Compugeek's test with the high-low thermometer and the insulated cooler. It might be possible to control the temperature sufficiently to give you more than one summer of "trunk life". It would be nice if someone in Texas or Florida has the equipment to do a similar test.

Craig.
Posted by: Compugeek

Re: Emergency rations for storage in a car? - 08/26/09 12:59 PM

The test is in progress. It's hard to resist posting partial data, but my High School Physics teacher would probably hunt me down if I did. smile
Posted by: Susan

Re: Emergency rations for storage in a car? - 08/27/09 04:48 PM

My knowledge of physics is minimal: if you step off a cliff you drop straight down, and if you're on a motorcycle and hit an immovable object, your body keeps going if there is no wall in front of you.

One thing on this subject has always made me wonder...

In extremes of temperature, would multiple+multiple+multiple layers of insulation prevent something from freezing or overheating, or would the outside ambient temperature still get to the item over time (maybe more slowly, but eventually).

To mitigate that, may I assume that you would need some source of coolness to keep something cool, and some source of heat to keep something from freezing?

I have always assumed this was the case, but when I ask people a question like this, I always get funny looks, like they're thinking, "Why would it matter?"
Posted by: paramedicpete

Re: Emergency rations for storage in a car? - 08/27/09 05:26 PM

Quote:
In extremes of temperature, would multiple+multiple+multiple layers of insulation prevent something from freezing or overheating, or would the outside ambient temperature still get to the item over time (maybe more slowly, but eventually).


Correct

Quote:
To mitigate that, may I assume that you would need some source of coolness to keep something cool, and some source of heat to keep something from freezing?


Correct
Posted by: ducktapeguy

Re: Emergency rations for storage in a car? - 08/27/09 05:38 PM

If the temperatures were to stay consistent throughout the day, then even with the best insulation the temperature of the item will eventually reach equilibrium without any extermal source of heating or cooling.

However, since the temperatures vary, what the insulation can do is mediate the temperature extremes. So if the peak temperature was 100 degrees, and the low was 50 (and assuming a balanced temperature graph on each side), a well insulated item would average around 75 degrees (+/- some amount), depending on the insulation and where in the car it is stored. Most likely you would see a shift in the temperature peak where the peak temperature of the item could be well into the cooling cycle of the ambient temperature. If youv'e ever opened a car door after a hot day and wonder why the inside is so much warmer than outside temperature, it's because the car itself is acting as an insulator.

Storing item in a styrofoam cooler or insulated bag is a cheap way to protect any sensitive items in a car. When I used to carry camera equipment in the car that's what I did. Even during the hottest day where the interior of the car would be too hot to touch, the items in the cooler were still comfortably warm. Not a very scientific test, but good enough that you could tell right away it was effective.



Posted by: unimogbert

Re: Emergency rations for storage in a car? - 08/27/09 07:10 PM

Originally Posted By: ducktapeguy


However, since the temperatures vary, what the insulation can do is mediate the temperature extremes. So if the peak temperature was 100 degrees, and the low was 50 (and assuming a balanced temperature graph on each side), a well insulated item would average around 75 degrees

Storing item in a styrofoam cooler or insulated bag is a cheap way to protect any sensitive items in a car. When I used to carry camera equipment in the car that's what I did. Even during the hottest day where the interior of the car would be too hot to touch, the items in the cooler were still comfortably warm. Not a very scientific test, but good enough that you could tell right away it was effective.



I've had different results.

One should consider that in summer the interior temp of the car is more like 120 or even hotter.

I've tried to protect electronics in a cooler during summer Colorado days. For a full day's heat soak a frozen bottle of drinking water in the cooler was required to keep the soft-sided cooler from letting the electronics get hotter than body temperature by mid-afternoon.

While it would be nice to have passive thermal control, I don't think it's easily achievable. But "easily" is a relative concept.

Other- I've used an IR thermometer to measure paint surface temps here. Black car read 175 while white car read 120 on a 99F summer afternoon. No black cars for my family!
Posted by: ducktapeguy

Re: Emergency rations for storage in a car? - 08/27/09 09:08 PM

True, one important thing I forgot to stress was you have to keep things out of direct sunlight. Once the items are in direct sun, then all bets are off because the radiation from the sun makes things a lot hotter than the ambient temperature, so temperatures can easily skyrocket. So usually that means storing things in a trunk, or at the very least throwing a towel over the cooler to keep the sun off. Also, one of those reflective sunshades in the windshield helps a lot, anything you can do to keep the sun out will keep your car cooler. I remember this issue used to come up on photography sites a lot, back when film was still popular.

Here's a pretty good graph showing the interior temperatures of a car over time.

http://www.randomuseless.info/318ti/temperature/interior_temps.png

Just by placing items in different areas of the car you can reduce the max temps by 20-30 degrees. The important thing to remember is all you're trying to do is buffer the temperature extremes. You will never be able to keep it at a constant temperature without active cooling, because given enough time, the temperature will always equalize. All you want to do is insulate it enough to make it through the hottest part of the day until it cools down again.

FWIW, those soft sided coolers never really worked for me, I think the zippers just couldn't get a good enough seal. I used one of those cheap styrofoam cooler that they ship frozen things in. The styrofoam was about 2" thick and it had a tight fitting lid. It seemed to insulate better than any other cooler I've ever used, plus it was free.

Posted by: unimogbert

Re: Emergency rations for storage in a car? - 08/28/09 12:15 PM

Originally Posted By: ducktapeguy


FWIW, those soft sided coolers never really worked for me, I think the zippers just couldn't get a good enough seal. I used one of those cheap styrofoam cooler that they ship frozen things in. The styrofoam was about 2" thick and it had a tight fitting lid. It seemed to insulate better than any other cooler I've ever used, plus it was free.



I concur. My softsided coolers don't help much at all. The hard-sided plastic cooler is a little better but the best cooler I've used was a disposable styrofoam job with tight fitting lid. Only lasted 15 years though. :-)
Posted by: GoatMan

Re: Emergency rations for storage in a car? - 08/28/09 05:48 PM

Perhaps a thermoelectric cooler would do the job. Some can both cool and heat. You would have to find one with a flexible thermastat to get the temperature right. If it is connected to a DC outlet that only powers up when the car is running, then it will work to either warm or cool the stored food until the car is parked. At that point it will then insulate it from the outside until it is powered up again.

This doesn't really help James since he doesn't want the bulk, but it seemed like a noteworthy idea.
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 08/29/09 01:54 PM

Okay, the results are in!

First off, here's my car in its usual parking spot:

It's 11:00 AM. I park facing east, and as you can see, the trunk will be baking for the rest of the day.

Here's inside the trunk (That cooler sat in the garage for a long time. I should have dusted it off before I took the pic! smile ) :

L-R: GHB and wide-brimmed hat, Cooler, Toolset and junk bag, unused floor mats, and reusable grocery bags.

And here are the results:

Code:
     Trunk     Cooler    Outside*
M    120/**    94/**     95/67
T    128/80    96/87     99/66
W    135/82    97/90     102/68
Th   137/84    94/89     106/68
F    137/86    97/95     106/73

Outside temperatures taken from US Weather Service reports.

*My car is garaged at night and doesn't experience the full low.
**I forgot to note the lows before I hit reset


As others suggested, a cooler doesn't prevent stuff from getting warm, it just smooths out the curve. What I didn't realize was that meant it would also delay things cooling off!

I've had four .7L bottles of store-bought water in that cooler for two weeks (along with 2 1L bottles in the GHB). I cracked one open just now, and other than being tepid, it tastes fine. I intend to continue that over longer and longer periods, to get a feel for how long I can leave water in my trunk.
Posted by: Yuccahead

Re: Emergency rations for storage in a car? Data! - 08/29/09 03:04 PM

Fantastic information.
Posted by: Russ

Re: Emergency rations for storage in a car? Data! - 08/29/09 05:24 PM

Good info. What thermometers did you use to measure the various high/low temps?
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 08/29/09 07:40 PM

Sitting on the junk bag you can see my little indoor/outdoor thermometer, and the wire leading to the remote sensor inside the cooler. It's just a cheapie that I've had for several years, but when I've compared it to my Radio Shack Wireless indoor/outdoor at home, it's always been within a few tenths.

"Trunk" is the "Indoor" reading, from the unit itself.

"Cooler" is the "Outdoor" reading, from the remote sensor.

"Outside" I got from Weather.com, "High" is at work, and "Low" is at home. I live in an area of San Diego called Normal Heights, about 10 miles from the coast, and work in El Cajon, about twice as far inland, on the other side of a low ridgeline.

Even for El Cajon, this week was hot. Twice we broke the daily record, and we came within one degree of the record for the entire month.

(I just noticed a typo. Friday was 106, also. All gooder, now. smile )
Posted by: scafool

Re: Emergency rations for storage in a car? Data! - 08/29/09 08:00 PM

Those are actually very good results Compugeek.
The cooler seems to be keeping what is inside it somewhere between 26 and 40 degrees cooler than the high temperature in the trunk of your car.

Would I be right to assume the cooler was fairly empty, and that if it was full the thermal mass might keep the stuff inside even cooler?

Or would that be incorrect and it would not matter much?
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 08/29/09 08:17 PM

That's a cheap little six-pack cooler. The 4 .7L bottles laying on their sides all but filled it. I couldn't put a fifth one on top of them and still close it.

I may pick up one of those styrofoam "disposable" coolers in the future, and see how it does. For now, I'll just be checking periodically to see how the heat affects the water.

I figure warm, slightly plasticky-tasting water is still better than NO water. Especially in SoCal.
Posted by: Susan

Re: Emergency rations for storage in a car? Data! - 08/30/09 12:23 AM

Thank you, 'Geek, for taking the time to do this. It certainly does answer some questions. And I hadn't considered the slowed cool-down time, either. Funny what you learn when you actually do it!

Sue
Posted by: Blast

Re: Emergency rations for storage in a car? Data! - 08/30/09 12:41 PM

Excellent data, Compugeek. You are really living up to your name (and I mean that in a very good way). I had been considering using a cooler like that to store emergency food in my truck down here in Houston, but it seems it would only extend the lifespan of the food a little bit.

So now I'm picturing a modified cooler with an automated vent fan that comes on two hours after dark to flush the hot air out of the cooler...

-Blast, dreaming
Posted by: Desperado

Re: Emergency rations for storage in a car? Data! - 08/30/09 01:03 PM

Could something like this 12V cooler be powered by something like this solar battery tender?

Place the cooler in the trunk, and run the wiring to the PV in the rear window of the car?

Kinda a stretch I know, but an idea...
Posted by: Russ

Re: Emergency rations for storage in a car? Data! - 08/30/09 01:13 PM

I only need the cooler to get me through hot areas and when I stop it's someplace with ice to rechill the interior.

Compugeek gave me a great idea with the indoor/outdoor thermometer though and for that I thank him. I ordered one of the wireless units and will instrument the back/storage area of the truck and may put a second sensor inside the cooler. First I get to experiment with temp differentials over time, but after that it can be used to monitor storage temps driving across the desert on trips. If cooler temps get too high it's time for more ice.

Unlike Compugeek's car, I don't have that big piece of glass acting like a greenhouse over the bed of my truck -- never liked hatchbacks and SUV's are definitely no better. To play on Desperado's solar panel idea -- maybe a larger flat panel could be used to block the light coming through those big pieces of glass and provide power to a cooler -- that might be a great idea.

I have a white pick-up with a white fiberglass bed-cover which should do a fair job of keeping the storage area to a max of ambient -- or so the theory goes. The black asphalt road may interfere, but to what extent? Now I can find out.
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 08/30/09 01:45 PM

That's why I chose that handle here. It emphasizes what I have to offer. I'm not a First Responder, nor much of an outdoor type, but if it involves data and cheap electronics, I'm there! smile

I'll be trying different things to try to ameliorate those temperatures. They can't be good for the Clif Bars in my GHB, either!

I'll start a new thread when I have more to report.
Posted by: Eugene

Re: Emergency rations for storage in a car? Data! - 08/30/09 06:38 PM

Originally Posted By: Desperado
Could something like this 12V cooler be powered by something like this solar battery tender?

Place the cooler in the trunk, and run the wiring to the PV in the rear window of the car?

Kinda a stretch I know, but an idea...


I've had a couple of those little 12v coolers, they draw 2-3A continuous and a 1.8W battery tender / 12v is 150mA. If you bought over a dozen of those battery tenders and paralleled them and had perfect sunlight and a small cooler it would work.

I used it when my wife had to take insulin shots. I bought the second battery tray for the diesel model of my truck and put in a second battery and isolator and had the cooler running off the second battery.
Posted by: UncleGoo

Re: Emergency rations for storage in a car? Data! - 08/30/09 08:22 PM

Originally Posted By: Desperado
Could something like this 12V cooler be powered by something like this solar battery tender?

Place the cooler in the trunk, and run the wiring to the PV in the rear window of the car?

Kinda a stretch I know, but an idea...

The manufacturer website says the cooler draws 48 watts. The solar charger puts out 1.8 watts. You'd need 27 of them to run it. How big's your back window? grin
Posted by: Susan

Re: Emergency rations for storage in a car? Data! - 08/30/09 11:01 PM

Would something like this work?
http://www.earthtechproducts.com/p2534.html

If you installed it in the roof of a car, it would look like a beanie with a propeller on top, but maybe in a trailer or something?
Posted by: timo

Re: Emergency rations for storage in a car? Data! - 08/31/09 02:22 AM

I think solar panels have pretty low amperage output (I'm not a solar expert) but maybe we could use this while driving around, using the suggested power supply, then switch it to solar power when the car is sitting with the engine off?
Maybe a panel would be enough to maintain a slightly lower temperature while we're at work?

http://www.electronickits.com/kit/complete/peltier/ck500.pdf

Make sure you read the whole article.
This seems to be right up our alley.

But there is no information on how long the project shown takes to cool down the air mass in the cooler.

Kind of funny though how the Aussies' used almost exactly the same size 'Esky/Cooler" as Compugeek!
Posted by: Russ

Re: Emergency rations for storage in a car? Data! - 08/31/09 02:24 AM

A lower tech approach would be to put a cover over the car so the greenhouse effect doesn't happen.
Posted by: Susan

Re: Emergency rations for storage in a car? Data! - 08/31/09 03:02 AM

Mylar emergency blankets for vehicles.

Hey, 'Geek! A new experiment coming up!
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 08/31/09 12:43 PM

When I go to the local fair or something similar, I have a large fabric remnant I put over that huge back window. I tuck it in at the edges as I close the hatch. It's just too much work to do on a daily basis . . . though I may be changing my mind about that.

The back window had tinted film on it when we* bought it. But there is no right-side mirror, and we had to remove the film (CA law - no tinted rear window if no RH Mirror). The temp differences were quite noticeable.

"Get a passenger-side mirror and re-tint the back window" is now MUCH higher on my "Someday" list.


*Late DW and I
Posted by: thseng

Re: Emergency rations for storage in a car? Data! - 08/31/09 03:58 PM

I once worked for a manufacturer of thermoelectric modules.

The very laws of nature cause them to be horribly inefficient power hogs. A good thermoelectric module requires a material that has a high thermoelectric constant, a low thermal conductivity and a high electrical conductivity.

God made it so that most good electrical conductors are also good heat conductors and vice versa.

They are good for “uh, compared to what?” types of applications where you need a little cooling over a small temperature difference.

On the plus side, the surface of the ceramic substrates makes a wonderful extra-fine knife sharpening stone.
Posted by: Eugene

Re: Emergency rations for storage in a car? Data! - 08/31/09 05:00 PM

Everyone seen those reflective things you can buy for the windshields, they look like bubble wrap between foil? You can buy rolls of that stuff at lowes/home depot. What you can do it buy a roll of that and line your whole trunk with it, espically the top/lid. I fif it in a truck, you cut panels to fit between all the structural steel then use aluminum duct tape to hold it in place, works very well to reflect the heat outward in the summer or inward in the winter. I did the whole cab of my truck and would not turn the heater on sometimes in winter as it would reflect enough of my body heat to keep me warm. I was going to cut panels out to cover the windows and tape the edges for use if I ever needed to shelter in the truck.
Posted by: Am_Fear_Liath_Mor

Re: Emergency rations for storage in a car? Data! - 08/31/09 11:43 PM


Thermoelectric coolers are not very power efficient and actually produce a lot of heat, which would tend to heat the space in the back of a vehicle and would raise the temperature in the vehicle boot even higher. Conventional compressor technology refrigeration would give the highest efficiency and keep any stored food at the highest temperature differential to the ambient temperature. Again a solar panel (i.e a 40W semi flexible marine PV panel), Solar Charge regulator, light activated relay and SLA Battery (i.e. Xantrex 300, which would a useful vehicle battery backup anyway) could be setup to power the a refrigerator such as the Waeco CDF-18 mini freezer/refrigerator. Food and water could be stored in Vacuum Flasks within the refrigerator.

http://www.minicoolers.co.uk/products/waeco/cf18.htm

As you can see it is not a cheap solution to a difficult problem.

Posted by: celler

Re: Emergency rations for storage in a car? Data! - 09/02/09 12:08 AM

Originally Posted By: Am_Fear_Liath_Mor

<snip>
http://www.minicoolers.co.uk/products/waeco/cf18.htm
As you can see it is not a cheap solution to a difficult problem.


Very interesting solution indeed. The advertisement says 35 watts power consumption. I'm thinking about converting that to amps and calculating how long an Optima deep discharge marine battery might keep that going before requiring a recharge. What I am thinking of is leaving off the solar charge option because of the inefficiency of the cheap solar chargers and the great expense of the ones that would provide a useful charge. If I could get away with just recharging that battery once a week, that might be a viable alternative.

You could also just add a second battery to your vehicle and add an isolator switch to make sure your fridge does not run down your main battery. This would allow the vehicle alternator to charge the additional battery. Although I suspect that this option may only be available to truck and SUV owners with over-engineered alternators.

Craig.
Posted by: turbo

Re: Emergency rations for storage in a car? Data! - 09/03/09 01:20 AM

Take another look at Compugeek’s data. There is a factor you are missing. Time!

People have used thermal mass of heavy and thick walls to delay the effects of temperature swings between night and day. The hot day temperatures slowly heats up of the heavy mass walls keeping the interior cool until the onset of night. At night, the cool night temperature reverses the process, cooling the exterior until the interior cooled off. This delayed the hot temperatures until night time. The mass delayed the interiors heat cycle. To keep the interior relatively cool all the time, the windows and vents would be opened at night. It also works the same way with insulation, i.e. the foam cooler.

If you would look at his temperature table again, you will see the average difference between his night time exterior temperature and his inside cooler temperature is between 21 degrees and 22 degrees. I bet these low temperatures were also at night. If he had opened the lid and cracked the trunk during the night, he may have kept his interior cooler temperature closer to his goal of 75 degrees. This opening could be accomplished with manual labor, thermal ram, or motor. All of which is less complicated, less expensive, and more efficient than electrical cooling.
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 09/03/09 01:28 PM

You're dead on about the temps. Lows were overnight, and the car was also in a garage, so its surroundings didn't even go that low. (I don't have a thermometer to use for the garage, though smile )

I thought about opening the trunk and cooler at night, but that's more work than I'm willing to do. (You got to know yer limitations.) I'm exploring other options to see what their effects are.

This week, I started with all four bottles frozen solid.
Posted by: scafool

Re: Emergency rations for storage in a car? Data! - 09/03/09 03:21 PM

What you start with should not matter. The final temperatures should still end up as a buffered and out of phase average of the high and low temperatures inside the car.

But it will still be interesting to see your results.
As they say, "A theory without an experiment is nothing but a faith."
Posted by: LCranston

Re: Emergency rations for storage in a car? Data! - 09/03/09 03:57 PM

Maybe a simpler Cheat would be to buy one of those Solar fans to keep the temperature in the car the same as the outdoor temp- then instead of fighting with 120-135 degree highs, your inside the car temp might be closer to your outside the car temps.

This would cool in the day, but not affect your night time temps...

This would work for hatchbacks and SUVs, probably not work for a standard trunk.....
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 09/03/09 10:00 PM

I've used various of those solar window vents. Even a pair of them does not move enough air to make a significant difference. When you can't leave a window open more than a finger width they're better than nothing, but not much.
Posted by: adam2

Re: Emergency rations for storage in a car? Data! - 09/05/09 08:08 AM

Originally Posted By: Desperado
Could something like this 12V cooler be powered by something like this solar battery tender?

Place the cooler in the trunk, and run the wiring to the PV in the rear window of the car?

Kinda a stretch I know, but an idea...


I dont believe that would work.
Thermoelectric coolers of the type pictured use several amps at 12 volts.
The PV module has stated output of 1.8 watts, which is probably a little over 0.1 amp at about 17 volts. And that is under ideal conditions, probably about 0.05 amp in practice.
At least 50 of those small PV modules would be needed and possibly as many as 100.

A 12 volt cooler could be powered from the vehicle battery, whilst the engine was running,which would help in the case of a vehicle in daily use.
However these 12 volt coolers are normally less well insulated than the non powered ones, therefore without power input the contents will warm up more quickly than in a regular cooler.
Posted by: ducttape

Re: Emergency rations for storage in a car? Data! - 09/08/09 08:22 PM

I use CLIF bars, they generally don't melt, compact for storage and more importantly, I like eat those. Sure they're not uber calorie packed like Datrek but I'll actually eat the CLIF. I do keep a pack of Datrek in the car but that's my last resort, something must really have gone wrong food.

Isn't that one of the top commandments to emergency food-get stuff you'll actually eat.
Posted by: Basecamp

Re: Emergency rations for storage in a car? Data! - 09/09/09 08:43 AM

This article looks interesting:

"Dispelling the myth of stored food in a vehicle"

http://www.alpharubicon.com/bovstuff/dispellcarfoodmyth.htm
Posted by: Compugeek

Re: Emergency rations for storage in a car? Data! - 09/09/09 12:58 PM

What exactly IS the concern for storage? That the food will become toxic? Or that it will lose quality, taste and/or nutritional value?