dry ice

[Homiesinheaven]

great, thanks so much for the reply. i plan on putting frozen water jugs on top. any other easy ways of covering it besides newspaper that will make it last longer?

[geospyder]

Not only am I a virgin this year but I'm also a virgin to dry ice. I just went over to the place today to get info. The info they had was that if you wanted to freeze items, put the dry ice on top. To keep things cool, put the dry ice on the bottom and then regular ice. The recommendation for storing the dry ice was to wrap it first in a poly bag (it actually comes this way) and then in newspaper or a towel. I'm doing the same as you - I have 12 one gallon containers of frozen water that I'll thaw as I need. At least that is the plan. So far the ten day forecast looks to be a little cooler than the past. There is even a 10 percent change of rain the night of the burn. But then again that is ten days out so thing can and will change.

[Homiesinheaven]

good preppin virgin! and thanks for the help. you're gonna have the time of your life.

[Jesus]

The more I think about it, the more I become convinced that my bulk pellets were all wrong. The total surface area must have been enormous, and with no wrapping to reduce air circulation against that surface. I bet, if I had instead used the same weight of the more common blocks wrapped in wax paper, it would have lasted the whole week and then some.

The issue, methinks, is what exactly happens in that "atmosphere" inside the box. When we close the lid after putting the DI in, it's mostly air, and it's moving around a bit. Slowly the air is then replaced by CO2, a slight pressure builds up, and excess air/CO2 is vented thru the inevitable tiny gaps here and there. What's really in there, and going on in there, after a day? 99% CO2? Circulation caused by the "boiling" of the DI into CO2? Thermosyphon circulation?
Once I understand some of that, perhaps I can make improvements. I think somebody mentioned... filling empty space with blocks of styrofoam or some such.

Thoughts? Knowledge? Reasonably coherent theories?

Dry ice brings the temperature of whatever is in contact with it down to −78 °C (−109 °F). What's important isn't so much block vs pellets as insulation vs no insulation. You want to insulate the dry ice with a bit of (small-bubble) bubble wrap, crushed newspaper, a towel, blanket or whatever that provides insulation so that it's not in direct contact with the food or inside wall or floor of the cooler. The more insulation between the dry ice and other things, the more slowly it will sublimate (turn to gas). You want more insulation than just flat sheet(s) of wax paper or other paper. Crushed/crumpled paper will do. A bubble-wrap shipping envelope, a towel or blanket is good. (Don't insulate the dry ice too well, or it won't keep your food cold.)

In terms of keeping things cold in a cooler, dry ice blocks vs pellets makes a relatively small (but still significant) difference. Likewise, in terms of keeping things cold in a cooler, block ice vs ice cubes makes a relatively small (but still significant) difference. Most important is whether you use ice or dry ice. (Dry ice absorbs 8943 Joules/gram as it turns to gas, while ice only absorbs 333 J/g as it turns to water. Research 'Latent heat' or 'Enthalpy of sublimation' or fusion, e.g. on wikipedia.) There is no point trying to keep the dry ice in an airtight container. Furthermore, it is more or less impossible; if you succeeded in doing so for any period of time, you'd have created a pressurized container that would be certain to explode!

After choosing dry over regular ice, most important is whether you insulate it within the cooler, keep the cooler out of the sun, or accidentally leave the cooler ajar. After that, most important is whether your cooler (or refrigerator) provides good insulation, is opened often, and is kept off the ground and out of the wind. Also important is that items at the bottom of your cooler will be colder than those at the top.

Don't worry about filling empty space with blocks of styrofoam or some such.

Bringing all your drinking water as ice and using it to cool is an excellent idea. It would be great if one of the stores in Reno sold this (bottles/jugs of frozen water) as a product to Burners at a reasonable price. I'd rather not truck my ice from the Bay Area to Reno. Square-ish plastic bottles/jugs won't burst if frozen.

Throwing blankets over your coolers also helps, if you didn't shell out for 5- or 7- day 'extreme' coolers. You can tell it works because when you pull off the blanket to get something out, you'll notice that the outside of the cooler is cool! It makes a regular cooler into an (inconvenient) extreme cooler. I use my nighttime 'fur' coat for this.

Hope this helps. Feel free to PM me if you have further questions.

[gyre]

i used 50 lbs of dry ice in an 80+ quart igloo marine cooler with block ice and filled in with bits.
No insulation around the ice.

My other cooler had block and crushed ice.

This would have been about right for my usual longer stay.
I got my shade right this year though and the ice lasted much longer.
I fully shrouded my tent and it was radically cooler inside the tent this year, relative to similar years.
Never opened a window.
Shade is the important thing.

I have also gotten better at packing without stuff that has to be refrigerated.
I switched over to the dry ice cooler as I left the playa.
The ice was still rock solid.
No dry ice left.
There was still some ice left days after I got home and the cooler was still in the car.
I was eating deli chicken after I got home that I bought before the burn.


fyi Cabelas has a thick rugged cooler for about $190.

[ygmir]

I built a cooler/insulator box (wood, expanded foam panels and Styrofoam totaling about 4" thick),for about 40 bucks..... put a cheap 100 qt. cooler inside, and, put 40 lbs dry ice in a soft sides cooler inside that. Then added frozen drinks and regular cubed ice.......the dry ice lasted 11 days, maybe 12 since I gave the last couple pounds left in there to a campmate....the ice was still rock solid, and, lasted 2 weeks total.......

[Elliot]

Thanks, Jesus! Good information, that!

This year I used no DI, but lots of pre-frozen water, Gatorade, and two gallons of milk. And I paid more attention to how I handled these things -- specially avoiding opening coolers just to see what's inside. Some tape and a pen is all that takes!

So now I feel better prapared to make good use of DI next year. There SHALL be ice cream on burn night!

[taz666]

Virgin burner trying to get prepped for 2010.
Just read the whole thread. I know all about DI, two esky (esky=cooler) systems, rotating frozen drinking water, and grey water recycling. I even know how to make ice-cream. My mum would be so proud of all the learning. Then I realised... BRC is in the USA, not in Australia. Dammit. I'm gonna go have some ice-cream now.
Thought some more and am now happy cause buying wet ice from Camp Arctica will help out some peeps.
So much to think about, so little time.

[taz666]

sorry, hang on, i just had a thought (my brain hurts a little :wink: )
Why is grey water removal such a problem? When i lived in the country, we had to make sure all water was sealed so it wouldn't evaporate away. To get rid of the grey water (except the residues) wouldn't you just leave the water in a big bowl in the daytime and let the heat of the sun turn the water into a cloud?

[EB]

Why is grey water removal such a problem?

Couple reasons why --

Between dirty dishwater, dirty shower water, half empty beers/sodas/etc, a person can generate quite a bit of graywater over the course of a week.

And even in the best of conditions for an evaporation pond -- direct, dust-free sunlight, evenly distributed load, wicking cloth -- evaporation is a slow ass procedure.

Add in the yahoo factor -- people pee in them, trip over them or as I've heard, use them as an impromptu slip-and-slides -- and you've got a real pain in the ass.

I think one poster here -- captain goddammit -- just packs his out without a second thought. Might be a good way to go...

[Boijoy]

agreed. I just take along a 5 ga bucket w/ lid and haul the stuff out. Mostly its just wash water.. the "other" dirty liquid goes into the portos.

[illy dilly]

i used 50 lbs of dry ice in an 80+ quart igloo marine cooler with block ice and filled in with bits.
No insulation around the ice.

Its my understanding that water melts dry ice? When you get mail order medications that need to be kept cold they come in a small cooler with a block of dry ice, if you want to get rid of the dry ice (kids, pets, people that don't know its dry ice can hurt their skin) you just drop it in a bowl of water, and it turns to gas and looks really cool but dissolves quickly.

Wouldn't you need to isolate the dry ice from the block ice?

[gyre]

As it dissolves it transfers the cold into the rest of the mass of ice.
I had solid dry ice for a long time, but usually only a day.
It still works to make things colder.
You aren't wasting energy until you reach absolute zero.

[ygmir]

As it dissolves it transfers the cold into the rest of the mass of ice.
I had solid dry ice for a long time, but usually only a day.
It still works to make things colder.
You aren't wasting energy until you reach absolute zero.

?
........

[gyre]

?
........

Use your words.

[ygmir]

I did, but, thought better of it...........

grin.

[gyre]

Very helpful, I'm sure.

[Jesus]

Lots of ideas for good insulation out there! Blankets, foam, cardboard, whatever! I keep my night-time 'fur' coat over my cooler stack; works great.

Thanks, Jesus! Good information, that! ...

Thanks! (blush)
Yeah-Labels! Organized stuff is usually a good idea anyway.

...Wouldn't you need to isolate the dry ice from the block ice?

YES! That's what you should do.

...You aren't wasting energy until you reach absolute zero.

That's not right at all!

As I said in my long post above,
Dry ice brings the temperature of whatever is in contact with it down to −78 °C (−109 °F)...

If you're trying to keep food & drink cool or cold, you SHOULD insulate your dry ice. If everything in the cooler gets extremely cold, heat energy will transfer into the cooler much faster, hence melting the dry ice much faster.

The only relevant exceptions would be if you're not simply trying to keep food or drink cool or cold.

Yes, I have studied the relevant physics in college.

If you object to 'Arguments from Authority', apply Fourier's law yourself:

* (Rate of heat flow) = k (Thermal Conductivity) x Area x dT (Temperature Gradient) / s (thickness).

If you plug in the numbers, you'll find that dry ice will last about FOUR TIMES AS LONG if the dry ice is insulated well enough within the cooler to keep the rest of the cooler at freezing (instead of at the temperature of the dry ice). (You only need to calcluate dT.) Therefore, you need 75% less dry ice per cooler if you insulate it than you do if you don't.

If you follow my advice above, you'll need far less than 50 lbs of dry ice to keep an 80-quart cooler full of food cold for 2 weeks.

[gyre]

That's a different reason for insulating.
I usually use a smaller amount of dry ice and the cold transfers rapidly, but the cooler stays cold for an appropriate time and temperature.

50 lbs was overkill for the better shade I had this year.
I didn't insulate and had dry ice driving home.
Hell, I had ice and cold water for days after I got home.

I know people using air space to insulate the dry ice from the food.

It all depends on what you're trying to do.

To my knowledge water doesn't dissolve the dry ice, warmth does.
The ice near the dry ice freezes solid.
I tried to rearrange things after I loaded the cooler, but it was all locked together already.
Stayed plenty cold enough.
With the shade I had, 20-30 pounds would be adequate.
Shade makes all the difference.

[illy dilly]

Jesus, thank you for backing me up.... Even I'm not sure I understand the whole second half.

All I know (from experience) is that if you get water on dry ice, it makes the dry ice and water turn into a cool cloudy vapor, leaving you with less dry ice. If your using block ice in a cooler (unless your cooler is then inside a refrigerated trailer) some of the the block ice will melt, which will also make your dry ice melt faster.
So my theory is just put the dry ice in a zip lock bag to keep it from getting wet. Get a bag that's a little bigger so as the dry ice turns to vapor it has room to expand with out popping the bag.
Jesus? what do ya think?

[Jesus]

Jesus, thank you for backing me up.... Even I'm not sure I understand the whole second half.

So my theory is just put the dry ice in a zip lock bag to keep it from getting wet. Get a bag that's a little bigger so as the dry ice turns to vapor it has room to expand with out popping the bag.
Jesus? what do ya think?

Sorry, I have to burst your bubble.
That's got nothing to do with any sort of chemical reaction between the ice and the dry ice; there isn't one. So keeping the dry ice from getting wet with a plastic bag won't do anything (other than provide a very small amount of thermal insulation) and it won't contain the vapor. (The vapor of a pound of dry ice would take up 9 cubic feet, and there's no good reason to try and contain it anyway.) The dry ice disappears into vapor because the water rapidly vaporizes it as it gets cold turns to ice.

Using air space to insulate the dry ice from the food is better than nothing, but is definitely not nearly as effective as using insulation. There's no good reason not to use insulation around your dry ice if you're trying to keep food & drink cool or cold with it.

[oneeyeddick]

Everything inside your cooler is gonna be frozen for a while, either way.

[Jesus]

Everything inside your cooler is gonna be frozen for a while, either way.

Not in the world I call reality.

[oneeyeddick]

You couldn't handle my reality, hayzeus.

[Thecatman]

Dry ice brings the temperature of whatever is in contact with it down to -78 C (109 F).

I know my response to this post is 6 months late but
last year (2009) I had a can of Ginger Ale freeze blow up in my ice chest at 2:30am. Scared the daylights out of me. The dry ice was on the bottom of the ice chest, covered with regular ice and then a towel and that soda along with a quart of OJ and a few other cans of soda and one can of beer still froze. The one soda was the only one that "blew up."

[Elliot]

I just saw a piece of rectangular steel tubing, 1 inch by 2 inch, that had been turned into almost round by water freezing inside it. The force of water freezing is tremendeous. When I saw that tubing, I finally "fully understood" how frost can crack engine blocks.

[Thecatman]

Look what its done to highways and interstates over the years in states that have freeze/thaw isuses

[skibear]

A large round ski lift tower near the base of a high speed lift
at Whistler filled with water. The expansion due to the water
freezing into ice cracked the welds midway up the tower causing
half the tower to fall down while people were riding the lift.

Lucky injuries to only a few riders were very minor.

Lots of force when ice freezes!

[bluesbob]

I was calling ahead, finding places that sell dry ice, and making plans for my trip & I came across this place.

Crystal Ice & Oil Co.
1345 W. 4th St.
Reno
(775) 323-5145

What makes this place so cool (pun intended) is that its open 7 days a week. Call for hours, but it means you can get dry ice on Sunday.

[gyre]

That's where most people go.
Good place.