Ice Chest Performance Enhancement
August 8, 2011
Filed under Camping News
Besides starting with a cold cooler, there are other steps you can take to optimize the performance of an ice chest. For example, rather than loading warm stuff into the cooler, place pre-chilled or frozen foods inside. Remember, this is not an active refrigeration unit; it’s only a passive insulated box. So whatever you put in there is going to affect the ambient temperature. Put ice inside, and the ambient temperature will come down; put warm foods in the cooler and the ambient temperature will rise. Obviously, it’s an advantage to start the trip with cold or even frozen foods inside the cooler.
Little known is the fact that not all ice is the same temperature. When you buy blocks of ice, you might get some blocks that are just barely freezing at 32 degrees F, and you might find some blocks that are significantly colder — even sub-zero. The temperature of ice doesn’t stop dropping just because the water freezes. Because warm air rises in the ice storage bin, when you buy ice take it from the bottom of the stack and place it in your cooler immediately.
Block ice melts more slowly than cubes, but cubed ice is much more effective at chilling individual items. If you want something to get cold fast, bury it in cubes, rather than just placing a block in the cooler and stacking the items next to it. Because cubes melt so much faster than blocks, our preferred method for multi-day camping trips is to use a block for general cooling and then use cubes to surround the foodstuffs.
To achieve ideal results, the more ice you put in the cooler, the better. Eliminate as much free air space as possible, because otherwise the ice will spend its energy trying to cool the air. For optimum performance, when loading the cooler place the block of ice and the food and drinks inside first, then distribute cubed ice over and around everything.
When the ice inevitably melts, don’t drain the water unless it becomes necessary to protect vulnerable packages of food. The water, although liquid, is still almost as cold as ice, so it does contribute to overall cooling of contents. Of course, this means that you must arrange food items so nothing becomes soggy. Cans, bottles and sealed hard-plastic containers can withstand direct contact with water. Keep other packages like food wrapped in foil or plastic wrap out of contact with water. I’m a little leery about allowing melt water to surround plastic baggies that might suffer a tear or other failure, but if you double baggie the food you’ll probably be safe. Just treat those packages with care. The advantage of having foods in a soft container is that the container becomes smaller as you remove food, whereas a rigid container takes up its full quotient of space whether its full or partially empty. And space inside a cooler is at a premium.
Dry ice is a whole ‘nother subject. Dry ice is the frozen form of carbon dioxide and is -109 degrees F. That is so cold that some coolers can’t handle it, becoming brittle and cracking when exposed to that extreme low temperature. Make sure your unit is compatible with dry ice, if you intend to use that type. Coleman, for example, says it’s okay to use dry ice in their coolers as long as it doesn’t come in direct contact with the liner. In a case like that, the dry ice needs to be kept in a separate container.
Yeti coolers are rated for dry ice without the need to isolate it from the liner. The Yeti information had this to say about the use of dry ice: “Dry ice gives off more than twice the cooling power per pound versus regular ice. This translates into dramatic weight savings. Consider using dry ice in any situation where extended cooling power is necessary such as extended trips or power outages during hurricane season. Dry ice can be used by itself or in conjunction with regular ice. Many pros pack a small amount of dry ice in their coolers, which will lower the temperature of the regular ice and contents. This combination drastically increases the length of time a cooler will keep ice. Because dry ice is so cold, there are handling precautions to keep in mind. Dry ice will likely freeze the contents in the cooler and can cause aluminum cans to rupture. It must be handled with protective leather or cloth gloves (oven mitts or hand towels also work) to prevent a freezing burn. It is also advised to keep dry ice away from small children. One other safety precaution to keep in mind is ventilation. Because dry ice is frozen carbon dioxide, when it sublimates (changes from a solid to a gas), it gives off carbon dioxide (CO2) gas. In a well ventilated environment, CO2 is not harmful, but without proper ventilation (riding in a closed vehicle) it can cause shortness of breath, and, in extreme cases, loss of consciousness.”
To help your cooler perform at its best, shield it from direct exposure to sunlight and don’t place it in a hot environment, such as inside a warm vehicle. Open shade works well. Move the cooler into a well-ventilated tent, or use a light-colored (or reflective) tarp or blanket to create a shady spot for the cooler if natural shade is unavailable.
And finally, limit access to the cooler. Every time you open the lid, some cold air escapes and warm air invades, so plan your raids on the food or drinks to get in and out while grabbing everything you need in a single foray.
One trick is to use two separate coolers — one for beverages and the other for food. Cold drinks are nice, but not essential. But food will spoil if you don’t keep it cold enough. This strategy will help protect your food because the food cooler will normally be opened less often than the drink cooler.
Read our Ice Chest Shootout article to see how various ice chest models performed during our cooling test.