Refrigeration for food during extended trips?

Greg D wrote: You could have stopped there since that's what I said. But thanks for your lengthy explanation and demonstration of your knowledge and ability to link to an article. I'll spare you my credentials but I do this stuff everyday. My point was that video was a marketing tool and quite misleading.

I really appreciate Mattm not "stopping there"

Perhaps you do it every day Greg, but some of us are learning and do not yet have this kind of knowledge.

Much appreciated Matt.

And Greg, I also appreciate your informative posts, but the sarcastic barbs?

A little sarcasm can be a good tool to make a point. Most people expect it from me. But some still get offended. It's just Internet chat.

I should be receiving a shipment in a couple days!

We'll test out the fridge next week. I have a second "house" battery is already wired in the van with isolator that charges when van is moving. I'll find out through use if there is any significant battery drain without solar in day to day use for a week or so at the Creek.

Longer term project will be to add solar. I don't have a good surface for a solar panel on the van (rocket box on top), but thinking about getting a lightweight flexible panel and rigging to a simple lightweight frame rather than bulky heavy and glass topped rigid panel for setting out when parked/camping.

The other brainstorm is to get a slew of 12v smaller size/smaller wattage peel and stick type panels to apply to the Rocket box and wire them up in parallel. Not an efficient construction, but it could work.

mountainhick wrote:I should be receiving a shipment in a couple days! We'll test out the fridge next week. I have a second "house" battery is already wired in the van with isolator that charges when van is moving. I'll find out through use if there is any significant battery drain without solar in day to day use for a week or so at the Creek. Longer term project will be to add solar. I don't have a good surface for a solar panel on the van (rocket box on top), but thinking about getting a lightweight flexible panel and rigging to a simple lightweight frame rather than bulky heavy and glass topped rigid panel for setting out when parked/camping. The other brainstorm is to get a slew of 12v smaller size/smaller wattage peel and stick type panels to apply to the Rocket box and wire them up in parallel. Not an efficient construction, but it could work.

Which fridge is that? Dometic CF35? I was thinking of snagging one of those.

20 kN wrote: Which fridge is that? Dometic CF35? I was thinking of snagging one of those.

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While dry ice is amazing for maintaining long-lasting refrigeration (not to mention the fact that it has a phase change directly from a solid to a gas at atmospheric temps - i.e. no messy standing water in the cooler!), I found one major drawback: in an enclosed space, the CO2 gas that builds up can permeate one's food, in particular the produce.

This means that soon you will think you are eating carbonated-enhanced everything!

For instance, on one trip all our blueberries and strawberries started tasting like a fizzy drink.....

mattm wrote: The Renogy with free shipping looks nice. One thing to consider for these panels is size/weight and how/where you'll be transporting them. I found anything above about a 60W panel was pretty bulky to fit in the back of my Jeep. If you're mounting it on a roof etc then not as big a deal. While a bit more expensive, those Renogy folding suitcases with the protective cover and built in angle adjustment look pretty nice. I DIY'd mine but wish I had a padded case to put them in. With the sharp frame edges and glass, raw panels are a bit of a PITA to transport. A padded case would make that less of a hassle. If one is really looking to top tier then opting for the much more expensive PowerFilm folding panels is worth a look. The ThinFilm solar tech, while much more expensive, can also be much more efficient than a similar mono or poly crystalline panel. See here: Jump Boxes certainly can save your butt however, I think it's better to leave your vehicle main alone and simply use a build specific battery box. The Jump Box battery is typically not designed for deep discharge (nor is your vehicle main) so using either one for supplemental power can shorten their lives considerably

That's a really interesting video and it kind of begs the question, why even wire the individual solar collectors in series anyway? Why not invent 12v collectors and wire them all in parallel? Is there truly absolutely no way to invent a single solar collector with an output voltage of 12v? Or how about 6v collectors wired in series-parallel configurations? There has to be a better way.

20 kN wrote: What about using the freezer to just freeze water in the unit for cooling? Instead of having the device plugged in 24/7, why not fill the bottom 4" with water, then put it in freeze mode, let the water freeze, then unplug it and use it as a cooler. When the water liquifies, just plug it back in and freeze it again. Not sure how efficient it is as a cooler, but if you can get the ice to last 2 days, that's 2 days off, maybe 4-8 hours on. That's a pretty good duty cycle and would save far more power than leaving it plugged in all the time.

Nope. Freezing water takes a LOT more energy (heat of fusion) than just keeping it cool, and is a LOT more inefficient (as the temperature gradient increases), so you'll be using a LOT more power on average. Your on/off periods will NOT be anywhere near equal (Law #2).

The three Laws of Thermodynamics:

1) You can't win.
2) You can't even break-even.
3) You can't quit the game.

I came across this article on a DIY electric cooler project using a peltier device. Kind of a fun idea and relatively low cost. He measured near freezing temps on 60watts of solar power.

His project is pretty ugly but if one wanted something more finished I'm sure the idea could be applied to a nicer box.

One could probably build a custom size cooler around 2" R10 rigid construction foam that would outperform most any commercial beverage cooler at 1/3-1/2 their cost.

MisterE wrote:I was living out of my trailer for 3 months in Bishop this summer in raging heat, and pretty quickly got tired of spending a lot of money on block ice. The Yeti's seemed prohibitively expensive, but Coleman has recently started producing a line of thick-walled coolers to compete with Yeti. I ended up buying a 55-quart "Esky" cooler - it was about a hundred dollars less than the Yeti, and even in 110-degree heat 2 blocks would last 4-5 days. Edit: it also has a hose attachment for draining water away from the cooler - I attached a 10' chunk of hose and ran it out one of the trailer access panels.

You got tired of spending a lot of money on ice so you switched to the Esky, or you had the Esky, you got tired of spending a lot of money on ice and so you are recommending not to use a cooler at all?

How much does a block of ice go for in the summer anyway in Bishop and elsewhere?

I have been seriously considering the freezer, but it seems like such a pain in the ass. I have a hybrid car which does not have an alternator, so charging a second battery is complicated. The vehicle uses a 308VDC battery which is charged by regeneration from the wheels, or from the motor, and then a 2000W DC to DC power converter steps the 308V down to 14.4 for the low voltage systems. But the vehicle is so complicated and advanced, I think adding a direct-connect second battery might cause problems. So between $400 for the freezer, $130 for a solar panel, another $200 for a battery, $40 for a charge controller, interconnection to charge the battery via the car, it seems like a cooler would be far less expensive depending on the cost of ice.

Ice is $2-5 per bag in Bishop or anywhere. It's easier to find cubed ice than block, block lasts much longer. Dry ice can keep your new block frozen longer if you can resist making bombs at camp.

Overall, unless you are going to be living completely off the grid for extended times and somehow have access to lots of fresh perishables, I think a cheap cooler far outshines any electric or propane fridge on price.

Extended surf and fishing trip to Baja?

Another thought, for my truck. I'm in the process of building wooden camp and gear boxes measured for an exact tetris fit under the platform. While I'm at it, I certainly could build a cooler. For the space mine takes up, it holds precious little. I could certainly make one to fit better and hold more within the confines of my space limits. Has anyone done this? I don't think it'd be very expensive at all. Making a good seal on the inside would be the hardest part and I don't think that would be too hard. Has anyone done this?

Another option I thought of was to buy a cooler, but freeze your own ice in your car. You can get a 450 watt phase changer for about $49 on ebay.

ebay.com/itm/Peltier-Thermo…

What I thought of was to build a small foam holder for water (like an impromptu cooler), line the cooler with a plastic bag, and then pour water in the bag with the phase changer underneath the plastic bag. The bag would ensure the water has direct contact with the phase changer for maximum heat transfer without spilling the water everywhere. Then just plug the changer into your car and wait for it to freeze. Easy day.

The big question I am having is how long would it take to freeze water, say from 40c to -10c at a rate of 450W? Say to freeze 7000g of water. Can it freeze water at all?

kirkadirka wrote:I like the dry ice option too for extended refrigeration time with a cooler. I find however, that placing the dry ice on the bottom of the cooler and then insulating that with a layer of ice works best. If placing the dry ice on top of everything it tends to freeze all your food rock solid.

When you're traveling, how do you find dry ice? I think the last time I have seen a store carry it I was about 14 years old. It seems pretty hard to find nowadays.

A 450 watt phase changer (or any other 450W load) run by a 12V auto electrical system would draw 37.5 amps. Not sure how long your car battery would last with that kind of load, and if you were running the car to keep the battery charged I wonder how long the alternator would last.

dryiceideas.com

Googling "dry ice denver" gave me the above link, along with a bunch of other sources. So I guess dry ice is still available out there, you just have to know where to look.

mark felber wrote:A 450 watt phase changer (or any other 450W load) run by a 12V auto electrical system would draw 37.5 amps. Not sure how long your car battery would last with that kind of load, and if you were running the car to keep the battery charged I wonder how long the alternator would last. dryiceideas.com Googling "dry ice denver" gave me the above link, along with a bunch of other sources. So I guess dry ice is still available out there, you just have to know where to look.

Most alternators can produce over 100A, and many cars can do 140A. some trucks can do 160A or more. A 38A load is not a big deal. There are plenty of people running 10,000 lb winches and 2000W power inverters off OEM alternators. I used to draw in excess of 1200A from two 205A alternators and five group 31 batteries back in the day.

Anyway, my car doesent have an alternator, it has an inverter which is rated for 2000W. Thanks for the link, I will bookmark that one.

20 kN wrote: Most alternators can produce over 100A, and many cars can do 140A. some trucks can do 160A or more. A 38A load is not a big deal. There are plenty of people running 10,000 lb winches and 2000W power inverters off OEM alternators. I used to draw in excess of 1200A from two 205A alternators and five group 31 batteries back in the day. Anyway, my car doesent have an alternator, it has an inverter which is rated for 2000W. Thanks for the link, I will bookmark that one.

Cars make for very expensive generators. IMO, anything that requires you to run your car is a bad idea.

I have a 110L Dometic "compressor" (electric-only) fridge in my truck camper, along with some other low-current goodies. My 210Ah battery bank, fully charged, can run the fridge for 2-5 days depending on outside temps. With a single 100W panel, that number goes up to a week or more. With a second 100W panel (200W total), I can run it indefinitely. Our fridge is big, too.

Solar is getting cheaper every day. Renogy makes awesome panels. You could probably build a 100W system for less than $300 (100W, PWM controller, ~80Ah AGM house batt) that would keep the fridge running as well as give you some extra juice for charging gadgets.

I also recommend that you keep the vehicle battery isolated. Get a separate AGM "house" battery. 6V AGM golf cart batts are an awesome, cheap option. You main "starter" battery really won't like being discharged below 50% or so. I'd much rather loose a fridge full of food than end up with a dead main battery and/or have to replace it prematurely.

Got one of these for my solar cabin... BEAST

vmaxtanks.com/

20 kN wrote: When you're traveling, how do you find dry ice? I think the last time I have seen a store carry it I was about 14 years old. It seems pretty hard to find nowadays.

Lot's of larger grocery stores still carry dry ice the problem is if you are in and out of the cooler frequently it dissipates fairly quickly.

Anymore I'm in the camp of wfscot, I cave a compressor fridge in my FWC camper and 200W of solar on top. The fridge runs all the time and the two house batteries stay charged with no problems. I use dry ice and coolers for big trips/groups when there is more food to transport than my fridge will handle.

Ensure there is sufficient ice to keep food in the cooler at 40 °F (4.4 °C) or underneath. Add more ice to the cooler as it dissolves. A 12V refrigerator like full cooler will hold the temperature for roughly 48 hours (24 hours in the event that it is half full).

Falkss Jamesss wrote:

Ensure there is sufficient ice to keep food in the cooler at 40 °F (4.4 °C) or underneath. Add more ice to the cooler as it dissolves. A 12V refrigerator like full cooler will hold the temperature for roughly 48 hours (24 hours in the event that it is half full).

I think the OP has figured it out in the 8 years since the post.

Marc801 C wrote:

I think the OP has figured it out in the 8 years since the post.

Lol