I'm trying to develop an inexpensive solar cooler for campingI've made a solar box COOKER before, using nested cardboard boxes painted black, with aluminum foil glued on the insideThe black surface absorbs heat from the sun's rays, while when the heat is re-emitted inside, the reflective foil tends to keep it inIt is a slow cooker which can develop about 325 degrees FNow I am thinking about trying the same idea invertedI know I won't be able to freeze thingsbut if I start with something frozen, could I keep it frozen this way without having to use those pre-frozen plastic containers of blue chemical? Anybody ever make a cooler like this? anybody know how? Any sites for plans? (not the cooker sites, I already have those.)Please include ideas for evaporative cooling using wet towels, if that has worked for you in the pastI'm trying to do this no-electricity, no chemicals, no bottle of gasI want to travel light.Thanks!
I guess it depends on what kind of propane burner, how hot it's going to get and how long it will be onA sheet of metal could work but if the burners get hot enough for long enough, it's conceivable that the wood could get hot enough to burnProbably unlikely, but possibleA layer of firebricks should be pretty bulletproof, as long as the wood can take the extra weight they'll add.
Distance.DO NOT USE OIL!!!! (for heat protection) The oil will heat to a higher degree than wood, damaging the woodAlso, most oils are flammableWood will expand and contract with hot/cold temperaturesEventually the wood will dry out start to crack maybe warp? Look for an attractive barrier as the one mentioned above, or create distance.
Although I'm familiar with what you are trying to do (and it does work) I don't know any way to do it light weight The clear sky is really cold and heat will radiate offBut if the air is warm you need a window to prevent convection (air circulation) from defeating your purpose If it gets cloudy and warm (as it will in some areas) you have a problemThere are naturally occurring ice caves where there is sufficient thermal mass that radiative cooling can keep water frozen year roundI think just super good insulation is the biggest keyIf you can open a box to the night sky when the air is cool and close it up during the dayEvaporative cooling is my favoriteIt does require that the air be reasonably dry - not good in humid climatesIt can be effective with something a simple as a wet towel, but a filter pad that air can flow through while wet is the best.
I guess it depends on what kind of propane burner, how hot it's going to get and how long it will be onA sheet of metal could work but if the burners get hot enough for long enough, it's conceivable that the wood could get hot enough to burnProbably unlikely, but possibleA layer of firebricks should be pretty bulletproof, as long as the wood can take the extra weight they'll add.
Distance.DO NOT USE OIL!!!! (for heat protection) The oil will heat to a higher degree than wood, damaging the woodAlso, most oils are flammableWood will expand and contract with hot/cold temperaturesEventually the wood will dry out start to crack maybe warp? Look for an attractive barrier as the one mentioned above, or create distance.
Although I'm familiar with what you are trying to do (and it does work) I don't know any way to do it light weight The clear sky is really cold and heat will radiate offBut if the air is warm you need a window to prevent convection (air circulation) from defeating your purpose If it gets cloudy and warm (as it will in some areas) you have a problemThere are naturally occurring ice caves where there is sufficient thermal mass that radiative cooling can keep water frozen year roundI think just super good insulation is the biggest keyIf you can open a box to the night sky when the air is cool and close it up during the dayEvaporative cooling is my favoriteIt does require that the air be reasonably dry - not good in humid climatesIt can be effective with something a simple as a wet towel, but a filter pad that air can flow through while wet is the best.
