TromboneAl
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
- Joined
- Jun 30, 2006
- Messages
- 12,880
Consider the TromboneAl supercooler, which has an outer layer of reflectorized bubble wrap:
The foil can only be helpful if it reflects some rays that strike the cooler, which would make the cooler hotter if not reflected. Since the sleeping bag is opaque, any such rays won't be transmitted by the sleeping bag, but as the sleeping bag heats up, it could emit infrared rays which would heat up the cooler, if not reflected by the foil. But the problem with this is that the cooler would also be heated conductively by the sleeping bag and the small air pocket between the cooler and the bag, and my guess is that this conductive heating would swamp any reflective effect of the foil. So, I'm saying no, the foil will not help keep the cooler cool when it's covered up by the sleeping bag.If it reflects infrared as well as visible light then, yes.
If you want to keep things cool, add the insulation to the bottom. Cold sinks. Added insulation on top will make little difference.
-ERD50
Hope those sleeping backs aren't wet...The cooler will be surrounded by pillows and sleeping backs, etc.
That's true for convection, but I think radiation and conduction are relevant here as well. If you put a hot pancake on a bunny's head, he/she will feel the heat. Or if you put your hand on the top of a block of ice, it will feel cold.
Just drink that 6 pack in the cooler before you start out. End of physics problem....(snip)...
If the cooler is covered with something opaque, such as a sleeping bag, does the shiny aluminum material make any difference for keeping the interior cold? IOW, does the reflector help, even if the cooler isn't in the direct rays of the sun?
Do you know how much ice costs? What, 99 cents for ten pounds or something exorbitant like that?Wouldn't it be simpler to just add more ice?
Imagine what he would be up to if he hadn't spent the last week chopping down a national forest into kindling!I never thought I could think such a thing but I believe it is time for you to go back to work Al.
I never thought I could think such a thing but I believe it is time for you to go back to work Al.
Wouldn't it be simpler to just add more ice?
Well, the objective is to not have to get ice as often (dig out the cooler, pour off the water, repack). Also, sometimes getting ice might mean an extra trip into town or an extra stop on the highway. Sometimes ice simply isn't available.
I never thought I could think such a thing but I believe it is time for you to go back to work Al.
Here in Hawaii we wrap our reflective foil in roofing materials.Consider the TromboneAl supercooler, which has an outer layer of reflectorized bubble wrap:
If the cooler is covered with something opaque, such as a sleeping bag, does the shiny aluminum material make any difference for keeping the interior cold? IOW, does the reflector help, even if the cooler isn't in the direct rays of the sun?
Here in Hawaii we wrap our reflective foil in roofing materials.
The foil both reflects the IR (from wherever it originates and propagates) while the quilted-bubble design provides an air-insulation buffer.
We're getting ready to put a new roof on our familyroom. The ceiling will be plywood cleverly routed to look like tongue & groove planks. Above that will be a two-inch layer of icynene foam. Above that will be a layer of plywood with radiant-foil insulation integrated into it. We're hoping for about R-15 to R-19.
I've crawled through our attics installing the rolls of radiant foil, and the difference is an immediate 10-15 degrees just underneath the foil.
As for that Internet source on IR propagation, consider that an IR imaging device can see through walls and other very non-transparent materials like black smoke. So either IR can penetrate through those objects or the Internet is somehow mistaken.
Apparently not. We've had the stuff up in some of our attics for over five years, and there's no reduction in performance.I've often considered adding a radiant barrier to our attic, but I've read that after a few years of dust accumulation, the radiant barrier is no longer effective. Have you had any issues with dust accumulation?