Polarbear Cooler Experiment

[RickG]

This is not a scientific experiment. No vittles were harmed.

So, I was wondering if I could take a 24 can size Polarbear cooler to STJ for next week's trip packed with frozen food. We are staying on STT the first night, so I need 36 hours of cooling power. I set out to determine how well this would work.

Experimental Equipment:
- 24 can size polar bear cooler (red)
- four one-quart round ziploc containers of water
- three techni-ice sheets
- one digital remote read thermometer

Procedure:
- Freeze four quart-sized containers of water in -10F freezer for three days
- Freeze three techni-ice sheets in -10F freezer for more than three days
- Pack cooler with techni ice and frozen water containers and chill packed cooler in -10F freezer overnight
- Take cooler out of freezer on Sunday at 9AM and insert remote read digital thermometer in center of polar bear cooler
- Ambient temperature was 72F

Observations:
- 9AM Sunday - 28F in cooler
- 9PM Sunday - 30F in cooler
- 9AM Monday - 34F in cooler
- 9PM Monday - 43F in cooler

Analysis: The internal temperature of the cooler was warmer than expected at 9AM on Sunday. At 9PM Monday the middle water container was still frozen while the side water containers were half-way melted.

Conclusion: No frozen food for us on this trip. Using this cooler it looks like 24 hours is the maximum time. The frozen food would likely stay frozen longer if:
- The cooler is pre-chilled open so that the internal area can get down to -10F
- Use another sheet of techni-ice
- Use square containers the leave less interstitial space
- Pack tighter with more frozen food

I may bring the cooler anyways to use on island as well as to transport materials that are not allowed by TSA. We would fold it and stow it in a carry-on suitcase on the way home.

Cheers, RickG

[waterguy]

Rick how about if you bought ice once you got to the island to replace the stuff that had melted

[RickG]

I want frozen food when I get to the villa. I think if I pack it tight with more food and techni ice we would be fine. But, the penalty for no cooler is low this trip with 2 adults and 2 kids rather than 8 adults. I just don't want to worry about it.

Next trip we'll be at the villa within 12 hours, which is a slam dunk. 24 hours would be fine. Longer? I'm going with a hard-sided Extreme cooler.

Cheers, RickG

[augie]

Rick - I don't have empirical evidence to back this up, but my gut feeling is that it would take hard frozen meats much longer to thaw than ice.

Also, a little dry ice on the front end could substantially delay the time before the temp in the cooler began to rise, no?

[PA Girl]

Just to throw out move info, I started with one layer of ti, followed by a layer of frozen meat, another layer of ti and so on. I also put sheets on all four vertical sides as well as one on top. In all, I think I used 8 sheets (some were cut down to fit short sides. This kept everything frozen for 36 hours.

We used the 48 can model and the sheets did take up a lot of room, there was not a spare inch for the extras I had planned to take (frozen drink cans) It was also heavy. It weighed in at over 40 pounds. (we checked it)

I took the little 6 pack size for our son's travel food. Because the food was not frozen and we openned it every two to three hours, the ti did melt after 12 hours.

[chicagoans]

I'm picturing Rick in a white lab coat...
"Thank you, Mr. Science!"

[RickG]

Rick - I don't have empirical evidence to back this up, but my gut feeling is that it would take hard frozen meats much longer to thaw than ice.

Also, a little dry ice on the front end could substantially delay the time before the temp in the cooler began to rise, no?

Ice is a better insulator than meat! Techni-ice is better than ice. Techni-ice is a near equivalent to dry ice (per Techni-ice).

<GEEK>
Lets geek out for a second, the amount of heat it takes to increase the temperature of a substance is called specific heat. You can get into more details such as volumetric heat capacity and thermal inertia, but I'll leave that to wikipedia. The specific heat of ice is around 2 and Beef Loin is 1.47, bigger is better, so ice wins. Oddly, liquid water has a specific heat of 4, so is an even better insulator.

I could not find Techni-Ice specific heat ratings, but Techni-ice claims performance equivalent to dry ice, if you believe that.

If you dig in, there oh so much more. That's why I did a simple experiment rather than try to do a spreadsheet exercise.

References:

http://en.wikipedia.org/wiki/Heat_capac ... t_capacity

http://www.engineeringtoolbox.com/speci ... d_295.html

</GEEK>

I could go up to 7 sheets of techni-ice, but I'd rather not leave that much on island. A cheaper route would be to buy a $20 wheeled Extreme cooler and leave it at the villa.

With 2 adults and 2 kids and plans to eat dinner at the villa just 2 nights the hassle is not worth it. November with 12 hour travel time, 6 adults, plus entertaining? Yes!

I'm still taking the 24 can-size Polar Bear cooler (the 48 can is too big and must stay at home this trip) because I want to use it for beach beverages and lunch. We are going to check it with sunscreen, bug spray, girl stuff and a couple of techni-ice sheets. It's going home folded in a carry-on suitcase.

Cheers, RickG

[augie]

The specific heat of ice is around 2 and Beef Loin is 1.47, bigger is better, so ice wins. Oddly, liquid water has a specific heat of 4, so is an even better insulator.

That would imply that as the ice melts, it becomes a better insulator.

Makes my head spin a little.

My curious side wants to do all kinds of experients, using water of various temps side by side with ice, and track the ability of each to retard increase in temperature.

The side of me that likes to lime on the beach says "well, what do you know about that? - it's not what I would have guessed".

Any bets as to which side wins out?

[tjwgrr]

I could go up to 7 sheets of techni-ice, but I'd rather not leave that much on island.

Last trip to STJ, we did 6 or so sheets of techni-ice in a polar-bear type cooler. I drained them the best I could in STJ before bringing them home.

What we also did was bring an extra suitcase and packed the polar-bear type soft-sided cooler in the center of the suitcase surrounded by clothing items. Couldn't pack the cooler too full, but it was still nice to have some good steaks and other meat/ cheese items from home. On return, I packed the soft sided-cooler with several bottles of liquor we purchased on STT and put all of it back in the extra suitcase- well insulated and protected- everything in good shape back on the mainland.

So far only United and US Airways are charging for a second suitcase....