Jugs of ice in the freezer?

[Jdege]

Originally Posted by Captain Bill

If the compressor is turned off and the temperature rises the cured meats will thaw first, followed by the steaks, and when those are thoroughly thawed the temperature will start rising again until the ice finally starts to melt.

If heat enters the system, the meat and ice will go through a number of phases in sequence.

1. Initially, both the ice and the meat will warm, keeping the same temperature.
2. When the temperature reaches the melting point of the melting point of the meat, the energy will go into the phase transition of the meat, until the meat is thawed.
3. After the meat has thawed, the temperature will begin to rise again, for both the ice and the meat
4. When the melting point of the ice is reached, the energy will go into the phase transition of the the ice, until the ice has melted
5. After the ice has melted the temperature of both the meat and the water will rise together

All of this assumes that the insulation is sufficient that the heat is entering the freezer slowly enough for the meat and the ice to maintain equilibrium.

The first phase, before the meat thaws, happens slower, if the ice is present, than if it doesn't. But it doesn't take all that long, because far more energy is involved in phase transitions than in simply raising temperatures.

[buzzstar]

Originally Posted by Captain Bill

A jug of water will freeze and thaw at about 0 degrees C (slightly less if not distilled water). Steak or any other animal tissue has an ionic content equal to about half strength sea water which means its freezing point is depressed about 1 degree C. If it's a meat that has been cured with extra salt or nitrate (like bacon or Ham) its freezing/thawing point will be depressed even further to perhaps -2 degrees C. Assuming one freezes both to -10 C, both will be frozen. If the compressor is turned off and the temperature rises the cured meats will thaw first, followed by the steaks, and when those are thoroughly thawed the temperature will start rising again until the ice finally starts to melt. The meat in your freezer will help keep your water frozen, but the water will not keep the meat frozen. It will however keep it cold.

You did not respond to the quiz, just one of the three scenarios.

[Captain Bill]

Originally Posted by Jdege

If heat enters the system, the meat and ice will go through a number of phases in sequence.




All of this assumes that the insulation is sufficient that the heat is entering the freezer slowly enough for the meat and the ice to maintain equilibrium.

The first phase, before the meat thaws, happens slower, if the ice is present, than if it doesn't. But it doesn't take all that long, because far more energy is involved in phase transitions than in simply raising temperatures.

No it doesn't assume that at all. The phase change occurs at a given temperature. The ice will not rise in temperature until the first phase change is complete. You are correct in that the time from the initial conditions to the first phase change will take longer with more ice(thermal mass) present than without it present. This assumes the rate of heat transfer is constant, which it isn't, but it depends on the delta T, so the colder the inside of the freezer is the faster heat flows through the insulation. The remainder depends in large part on surface area of the freezer walls. All that would have to be calculated for any individual freezer configuration. In a scenario where the temperature of the freezer does reach the phase change temperature of the meat, the meat would absorb heat from the ice if the ice was warmer than the meat, thus delaying the ice reaching its phase change temperature. Hence my statement that the meat will save your ice. Now add 10% salt to the water and your water will save your meat. Repeated freeze thaw cycles do terrible things to the flavor and texture of meat so it is better for your food to depress the freezing point of the water if you are likely to have get yourself into that situation.

[SV THIRD DAY]

One of the problems with Chat Room forums is that the same Dock/Cruise rumors get brought up and discussed over and over and over. It's like what was said last month was never said or discussed in a 20 page thread. So a new one emerges as if talking about it again will change the answer. The same folks then give the same pro/con thoughts on the subject and the world continues to spin as we all look for an excuse to either not work on our own boats or as a diversion if posting when we should be "working"

The first few times I sit down and take an hour to share real life test data to disprove the myth. But science and data doesn't impress some, so they don't believe the data and some will even call you a liar for your efforts. (As if I somehow benefit from being technically incorrect about a topic I make my living at on a public forum...but go figure...it's how the internet works in a world of Fake News).

So still you try. But each time the myth/rumor comes up your energy (and give a crap factor to correct it) goes down. I mean how many times do you have to prove gravity and thermodynamics before people choose to believe it? Personally I'm at about 3 times. Once I deal with the same myth/rumor 3 times my ADD personality gets bored with it and just moves along to something new. My answers go from long data filled posts to short sweet quickies.

Cliff notes Version:
1. Heat In...Heat out.

2. If your thermostat and refrigeration system is not set up to take advantage of the Eutectic properties of a freezing and defrosting jug of water then you could actually be using MORE power while trying to save it. It's all about controlling the Eutectic solution it can either hurt you or help you. Which is why some "sware by it" while others say "it doesn't help" when they tried it.

3. Front opening units have different properties than top loading, so don't confuse the two.

[buzzstar]

Originally Posted by SV THIRD DAY

One of the problems with Chat Room forums is that the same Dock/Cruise rumors get brought up and discussed over and over and over. It's like what was said last month was never said or discussed in a 20 page thread. So a new one emerges as if talking about it again will change the answer. The same folks then give the same pro/con thoughts on the subject and the world continues to spin as we all look for an excuse to either not work on our own boats or as a diversion if posting when we should be "working"

The first few times I sit down and take an hour to share real life test data to disprove the myth. But science and data doesn't impress some, so they don't believe the data and some will even call you a liar for your efforts. (As if I somehow benefit from being technically incorrect about a topic I make my living at on a public forum...but go figure...it's how the internet works in a world of Fake News).

So still you try. But each time the myth/rumor comessage up your energy (and give a crap factor to correct it) goes down. I mean how many times do you have to prove gravity and thermodynamics before people choose to believe it? Personally I'm at about 3 times. Once I deal with the same myth/rumor 3 times my ADD personality gets bored with it and just moves along to something new. My answers go from long data filled posts to short sweet quickies.

This highlights a couple of problems with CF, and possible corrections. 1/ As some (I have no clue as to the percentage) of us seek more stars and the necessary larger number of posts, we tend to post whenever there is an opportunity, perhaps too often adding nothing to the discussion. 2/ There is no real way to agree or disagree with a post factually or otherwise except by another post. 3/ Many of us, myself included, have enough information about lots of stuff, enough to have opinions, but often not enough to be correct, understandable, or knowledgeable, let alone authoritative. 4/ The moderators probably know this, but what percentage of the posts (probably a large number) are by what percentage (probably a relatively small number) of the membership? 5/ I suspect the benevolent, mostly hands off, involvement of the moderators is one of the factors in making this a popular place (to post, to follow, or to research) but should/can the rules be eased or tightened in a beneficial way? 6/ There is no doubt that more ideas are out there.

[tmcdonagh]

I strongly caution folks from using dry ice on boats. Carbon dioxide is heavier than air and will fill the boat displacing oxygen. This is just as deadly at carbon monoxide, well almost as deadly.

[Cadence]

The whole thing about which will thaw first is off point. The reason for the jugs of water are to displace cold air with something that doesn't spill out of the freezer when opened.

Beyond that, if the freezer goes tits up, it's better for keeping your beer cold and maybe the steaks cool till you cook them.

All the academia about thaw time is moot.

[skipgundlach]

I still don't know whether I should take out or merely empty my few gallons' worth of OJ jugs...



Skip

[sailorboy1]

Originally Posted by skipgundlach

I still don't know whether I should take out or merely empty my few gallons' worth of OJ jugs...



Skip

Take them out.

[sailorboy1]

How fast the ice melts depends on how much alcohol is in the glass and hot out it is, factoring in how fast you drink it.

How fast the steak thaws depends on how soon you put it on the grill in relationship to the drink about be.

Really now people

[CSYChip]

Holding plate systems use a mix of water and antifreeze to "hold" temperature. Most foods require a temperature well below ice to be stored for any length of time. Having a large often mostly empty freezer, I have a collection of both ice jugs and antifreeze/water jugs. It makes no noticeable difference in power consumption once they are all frozen but the added mass reduces short cycling of the compressor. The combination also helps ride out temporary power loss when weather and other factors conspire against my solar panels.

[Cadence]

Originally Posted by CSYChip

Holding plate systems use a mix of water and antifreeze to "hold" temperature. Most foods require a temperature well below ice to be stored for any length of time. Having a large often mostly empty freezer, I have a collection of both ice jugs and antifreeze/water jugs. It makes no noticeable difference in power consumption once they are all frozen but the added mass reduces short cycling of the compressor. The combination also helps ride out temporary power loss when weather and other factors conspire against my solar panels.

Don't mistake the antifreeze for cool aide. A Jim Jones mix.

[buzzstar]

Originally Posted by tmcdonagh

I strongly caution folks from using dry ice on boats. Carbon dioxide is heavier than air and will fill the boat displacing oxygen. This is just as deadly at carbon monoxide, well almost as deadly.

Carbon dioxide can be deadly, and does behave as described, but CO2 is less deadly than CO. As I understand it, the CO not only means less oxygen in the air taken in by the lungs, but will actually attach to the hemoglobin that would normally carry O2 (oxygen) to the cells, thus replacing it, and it will also accumulate in the body. CO2 does not do this, but it can mean there is less O2 in the air that the lungs take in.

[newhaul]

Originally Posted by tmcdonagh

I strongly caution folks from using dry ice on boats. Carbon dioxide is heavier than air and will fill the boat displacing oxygen. This is just as deadly at carbon monoxide, well almost as deadly.

The ammount of dry ice most would use on a sailboat would actualy be.a mnimal risk during most of the years cruising there is more than sufficient ventelation. The air exchange rate when sailing with even the companionway open would negate any buildup of.carbon dioxide. Most CO detectors will also go off with an increase of co2 long before it reaches dangerous levels.

[tmcdonagh]

Originally Posted by buzzstar

Carbon dioxide can be deadly, and does behave as described, but CO2 is less deadly than CO. As I understand it, the CO not only means less oxygen in the air taken in by the lungs, but will actually attach to the hemoglobin that would normally carry O2 (oxygen) to the cells, thus replacing it, and it will also accumulate in the body. CO2 does not do this, but it can mean there is less O2 in the air that the lungs take in.

True, true. I chose not to go into details. Increased levels of CO2 will also form carbonic acid in the blood stream, lowering pH. With reduced pH, hemoglobin binds O2 less effectively.