49

Short answer: A cooler containing more ice and less frozen food will last longer than a cooler containing all frozen food. With frozen contents of a given mass, the length of time a cooler will stay cold is proportional to the latent heat of fusion of the contents. The latent heat of fusion of water ice is 334 joules per gram. ASHRAE (the American Society ...


30

If you look for the manufacturer's promises for these "passive" boxes (there is absolutely no cooling, just the attempt to keep the cool in - called isolation), they usually state something around 24h to keep things cool. You don't even have to start thinking how the manufacturer got to this number. There is no way to use it in the way you proposed because ...


20

I'm assuming the amount of food you want to take and your coolbox size is fixed, so the question you're asking is really whether you should fill every remaining gap with ice, or whether you should leave it as air. The answer to this is that air inside your coolbox is a big problem, and will majorly contribute to thawing. The specific heat capacity of air ...


16

The short answer is that you need to get rid of all the air from inside your ice box. So no, frozen food by themselves won't work. The easiest way to deal with this is to let an outfitter prepare the food. Even for a private unguided trip, you can get outfitters to do all the logistics work from put-in to take-out (that's what we did when I rafted the Grand)....


5

I will not comment on the general feasibility of your plan. However, I did a little research about the specific heat of various materials, and the results are actually pretty interesting. We are looking at how long a given item will stay cold. Said another way, we are interested in how much heat energy the food or ice can absorb while remaining cold. The ...


3

Ask three different raft guides and you'll get three different answers---gnarly rivers have been rowed on all three setups and it ultimately comes down to personal preferences. That being said, each system has distinct (dis)advantages that I'll discuss, which can be useful to know when first starting out. Oar Locks The classic technology since time ...


3

My recommendation would be to use caltopo.com, which is a quick way to check water levels. Checking this option will show you available data from a lot of water gauges all over the country: Each little circle is one water gauge, and clicking it will show you the water levels over the past couple of days. This is an example from the Merced River, measured ...


3

To give two more numbers that can serve as rough guesstimates which make clear that cooling for 18 days on a tour is likely unfeasible. I'm assuming hiking tour as it isn't specified. One rule of thumb for shipping biological (research) material on dry ice in the type of styrofoam containers used for this is to pack 1 kg of dry ice per day. Which would be ...


2

Another factor to keep in mind: Heat rises--the warmest part of the ice chest is on top. Thus you have ice there and food underneath it so it's ice that melts rather than food. That being said, you're asking more of an ice chest than it's capable of. Even stuff like the Yeti chests can't do this.


2

The water temperature, which used to get as warm as 80 degrees F, is now icy-cold all year and averages around 42 degrees F And hey, what do you know, refrigerators are often set at 42F... So... multiple smaller high quality coolers, with dry ice and your frozen meals. Do not open them until needed, and try not to need them until the previous cooler is ...


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