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Do I Really Need Refrigeration? |
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When we go to buy a boat we look at many things such as color, engineering, design etc. but few of us stop to think about refrigeration. It isn't until we've made our first shakedown cruise that we begin to wish for the comforts of home such as ice cold drinks and the conveniences of refrigeration. The cook complains about the space the blocks of ice take up and the crew complains about eating canned food as a steady diet. After listening to these complaints the captain usually does one of two things buys earplugs or rushes out pell-mell and buys the first refrigeration system he finds. Before you do this you need to ask yourself a few questions: Is a refrigerator really a practical investment for me? The answer to this would depend on the way your boat is used, Do you take day trips weekend trips, or long cruises? If Your boating is mainly day or weekend sails then an ice box is quite adequate. For a day's sail a bag or two of ice will drop the temperature of the box instantly and food will stay fresh for at least 24 hours. If you plan to spend the weekend, then you will need more ice probably a block or two, These will keep food fresh and drinks chilled for two or three days, If your boating tends to be cruises longer than two or three days and your palate craves fresh meats and vegetables, then refrigeration might be the best for you. How long will food last in an ice box? If you're like most people, you stock up on supplies at the home dock, and if you're like most people, you tend to believe that as long as you have ice in the ice box then the food will stay fresh. This misconception has led to a lot of good meals for the fish. I've always wondered how many pounds of hamburger get dumped overboard. Most people don't realize that the temperature in the box can be no colder than the ice itself. Frozen water (ice) can only produce a maintained temperature of 32° F and that is only on the surface of the ice itself, You must maintain a certain temperature to achieve the maximum storage life for most perishables For Example:
To maintain the foods at the above temperatures in an ice box they would have to be embedded in the ice. Refrigeration on the other hand can provide temperatures within a box as low as -25° F. After constructing a four cubic foot box with 2 inches of Styrofoam insulation on all six sides, I proceeded with three separate tests measuring temperature for three days with a recording thermometer.
The temperature readings overlaid on a single graph are representative of a three day cruise where the box lid was never opened and the outside temperature stayed at 70 degrees F. As you can see, with the ice box replenishment of ice every 46 hours, adequate cooling is provided for many foods. The performance of an ice box can always be improved by adding as much ice as you have room, but remember the box will not maintain a temperature below +32° F. To keep meats frozen the temperature must be below +26° F. A small 12-volt system, after the first day's pull down phase works well as a refrigerator if there is sufficient battery power. When shore power is connected 24 hours before sailing, this system is better than a straight ice box. If you wanted to keep perishables over an extended period of time a freezing compartment would be necessary. It is obvious that the engine drive system is the best, but it is also the most expensive unit to buy and the most difficult to install and maintain. If you study this chart closely, you can see that for the weekend sailor the old reliable ice box is probably the best way to go, but if cruising is more your style, then refrigeration will probably prove to be a wise investment in the long run |