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! ...
Yeah-Labels! Organized stuff is usually a good idea anyway.
illy dilly wrote:...Wouldn't you need to isolate the dry ice from the block ice?
YES! That's what you should do.
gyre wrote:...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 âˆ’78 Â°C (âˆ’109 Â°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.