Study of the Heat Retaining Capacities of Insulated Jugs

摘要

The purpose of the report was to determine the effectiveness of thermos containers, vacuum and insulated, in keeping food hot during cold weather operations. Conclusions: An insulated thermos jug of 18.2 quart capacity will keep food hot for at least 4 hours and adequately warm for periods up to eight hours. The rate of fall in temperature of the food contained is approximately 0.3F per quart per hour, the rate being in part dependent upon the temperature of the food at the time it is placed in the container. Vacuum bottles also have excellent heat-retaining properties but due to their fragility and cost are not as suitable for transportation of hot food as the more durable insulated jugs. Insulated jugs are effective in keeping food hot and provide an excellent means for the transportation of foods during extreme cold weather. The larger insulated jug, 18.2 quart, is more efficient than the smaller jugs of 3.5 and 7.6 quart capacity. To provide for most efficient performance, thermos containers should be filled completely. (Author)