Dry Ice in Icebox

[StuM]

Originally Posted by wguinon

Your reference gives 149 btu/lb at the triple point, -70F and 5 atmospheres.

You're correct, that is the wrong figure to use. It is actually much higher than 149 BTU/lb for Dry Ice.


https://www.continentalcarbonic.com/...et---msds.html


Latent Heat of Sublimation (Dry Ice) - 246 BTU/lb. (-110° F)


Which makes more sense when you look at my first reference
"
Kilo for kilo, dry ice has a refrigeration capacity equivalent to 170% of that of regular water ice."

Taking your 144 BTU/lb for water ice:

246/144 = 1.708

[StuM]

Originally Posted by GordMay

Yes, "Keep dry ice in a vented space.";

It's also worth bearing in mind that average human exhales about 2.3 pounds of CO2 on an average day. How long does a 10lb block of dry ice take to sublimate in a well packed ice box?

[JaaaPeee]

We tried dry ice once, with funny result: we thought the baby carrots and grape tomatoes had all spoiled, because they were "bubbly." After we left them out for a few minutes we had a good laugh about unexpected carbonated veggies.
After that we went back to blocks when available, gallon milk jugs more often.

[a64pilot]

I used dry ice one time when the fridge was down and it worked great. I liked it. Lasted way longer than ice and kept thing frozen, ice cream for example. And water ice can’t do that.
However there is confusion on this thread with advice to buy CO detectors and such, dry ice is the dreaded green house gas, CO2 and other than it displaces O2, it’s not really dangerous, however CO is very dangerous, it binds to hemoglobin and prevents the uptake of O2.

While there have been many deaths from CO2 from volcanic eruptions, it’s unlikely on a boat. I guess it could happen but as we have never heard of a case, I think it unlikely.

[Maka]

I prefer GEL packs, 5 - 6 inches square when frozen laid flat.
They are perfect for recycling through a 12V freezer like truckers use.
Excellent for keeping an ice box cold.
I switched to this when my onboard built in fridge system died and was going to cost a fortune to replace.

They stay frozen / cold longer than water. Can slip between items to keep cold even on all sides. Reusable.

[Secondshift]

Originally Posted by a64pilot

I used dry ice one time when the fridge was down and it worked great. I liked it. Lasted way longer than ice and kept thing frozen, ice cream for example. And water ice can’t do that.
However there is confusion on this thread with advice to buy CO detectors and such, dry ice is the dreaded green house gas, CO2 and other than it displaces O2, it’s not really dangerous, however CO is very dangerous, it binds to hemoglobin and prevents the uptake of O2.

While there have been many deaths from CO2 from volcanic eruptions, it’s unlikely on a boat. I guess it could happen but as we have never heard of a case, I think it unlikely.

Guilty as charged. For fear of generator/engine exhausts back flowing into our cabins we've installed CO sensors that as indicated WILL NOT detect CO2.

Apologies and Regards

[ArmyDaveNY]

Originally Posted by a64pilot

CO2 and other than it displaces O2, it’s not really dangerous

While there have been many deaths from CO2 from volcanic eruptions, it’s unlikely on a boat. I guess it could happen but as we have never heard of a case, I think it unlikely.

Exactly! Dry Ice is often used indoors with no issues. Haunted houses in particular use exceptionally large amounts of it indoors and with no problems.

[GordMay]

Originally Posted by StuM

It's also worth bearing in mind that average human exhales about 2.3 pounds of CO2 on an average day. How long does a 10lb block of dry ice take to sublimate in a well packed ice box?

Indeed. (good point)
According to the Dry Ice Corp*:
How Long Does Dry Ice Last?
Well, unfortunately there is no end all be all answer to this question, as it depends on the size of the block and the conditions in which it’s being kept. What we can tell you, however, is that dry ice sublimates at a rate of about 5 to 10 pounds per day when kept in a typical ice chest. This rate accelerates to 5-10 pounds per 3-5 hours outside, and when it’s placed in liquid, the same amount can disappear as quickly as 15-45 minutes.
* ➥ How Long Does Dry Ice Last?

[StuM]

Originally Posted by GordMay

Indeed. (good point)
According to the Dry Ice Corp*:
How Long Does Dry Ice Last?
Well, unfortunately there is no end all be all answer to this question, as it depends on the size of the block and the conditions in which it’s being kept. What we can tell you, however, is that dry ice sublimates at a rate of about 5 to 10 pounds per day when kept in a typical ice chest. This rate accelerates to 5-10 pounds per 3-5 hours outside, and when it’s placed in liquid, the same amount can disappear as quickly as 15-45 minutes.
* ➥ How Long Does Dry Ice Last?

That quote appears to be talking about just a block of dry ice in an ice chest. Further down is a more relevant passage which describes the way it would be used when keeping food cold:


You can also wrap the dry ice block in plenty of layers of newspaper (carefully, of course), and the newspaper will act as a surprisingly effective insulator. Going another step further, keep some regular water ice alongside your dry ice and both will last even longer!

[a64pilot]

The thing I like about dry ice was it was easy to put enough in the freezer wrapped in paper to last well longer than the weekend, nothing got wet and it kept the freezer side frozen, I mean rock hard ice cream frozen.

Then I got the reefer fixed and didn’t need it anymore.
What dry excels in my opinion Is the weekend user that has good access to it, we bought ours at the Public’s in Panama City, bought food and dry ice all at the same time.
If we were only weekend sailors, no need for a high dollar reefer system

[GordMay]

Originally Posted by StuM

That quote appears to be talking about just a block of dry ice in an ice chest. Further down is a more relevant passage which describes the way it would be used when keeping food cold:
You can also wrap the dry ice block in plenty of layers of newspaper (carefully, of course), and the newspaper will act as a surprisingly effective insulator. Going another step further, keep some regular water ice alongside your dry ice and both will last even longer!

Extending that same quotation:
"... Just make sure that the cooler isn’t sealed tight and that the place you’re keeping the cooler is well-ventilated. Those are all things we learned way back in Dry Ice Safety 101. You can also wrap the dry ice block in plenty of layers of newspaper (carefully, of course), and the newspaper will act as a surprisingly effective insulator. Going another step further, keep some regular water ice alongside your dry ice and both will last even longer!"

[StuM]

Originally Posted by GordMay

Extending that same quotation:
"... Just make sure that the cooler isn’t sealed tight and that the place you’re keeping the cooler is well-ventilated. Those are all things we learned way back in Dry Ice Safety 101. You can also wrap the dry ice block in plenty of layers of newspaper (carefully, of course), and the newspaper will act as a surprisingly effective insulator. Going another step further, keep some regular water ice alongside your dry ice and both will last even longer!"

Has a look at their "Dry Ice Safety 101".



1. "DO NOT store dry ice in a completely airtight container. (We’ll get back to this in the next section.)"


But they don't "get back to this". Presumably that is to stop a pressure build up and a potential explosion? I doubt you would see that with an ice box.



2. "Proper storage ventilation for dry ice safety is crucial because of all the carbon dioxide that dry ice emits as it sublimates. Normal air is only 0.35% carbon dioxide, and any concentration higher than 0.5% can start to get dangerous."


Only out be a factor of 10!

[thinwater]

Originally Posted by tmcdonagh

Due to the potential asphyxiation risk, I will not use dry ice on my boat.

Tom

The average person exhales about 2.3 pounds of CO2 per day, so it is roughly equivalent to having 2-3 extra people in the cabin or running the stove long enough to burn a few pounds of fuel. If it is summer and you need dry ice, windows are open. If it is winter, you don't need the dry ice.


I don't use it, but I would consider it a minor thing.

[captprogreso]

Here in mexico i used to fill topperware with dry ice and the put them in the ice box, after 5 days if you use 1/3 of this space with this thing you will still have deep frozen meat, if you can put that topperware on the bottom of the fridge and below them put a sheet of that thing that you can find in home depot for keep a space below them so the air can go around them.
Here you can buy in blocks or you can take your topperware and they will fill them. Be carefull the ice is so below 0 that can harm your skin. The evaporative of this thing is so low you will never notice the gas is coming out.
Very safe.
If you like to take your rum and coke with ice, take your ice box to them and put a layer on the bottom, then but a lot of plastic sheet and then bot over it the ice cubes bags, after 4 day you will still enjoy it.
For drinks use as follow, use one ice box only for storage the ice cubes bags, and take only one bag and put it in another ice box that you will open and closed several times each days.

[Jaqun]

Thank you all. We will consider for our next trip.