2 ms·

But which method would take longer? Heating five 55-gallon drums to 100C each, or boiling one barrel of water until the battery is dead? Which is more efficien

• tzs 3y ago
  My first guess is that heating multiple drums to 100℃ would be faster than boiling one drum. This is based on the rate of heat exchange by contact when two things of different temperature touch is proportional to the temperature difference. When the water is at 100℃ the difference between it and the heating element should be less than when the water is colder and so it should be transferring heat slower. By switching drums you are spending more time with the heating element in colder water so can transfer more energy. However there may be other factors. First, dH/dt = k ΔT, but k depends on the particular two things that are exchanging heat. I don't know if the k for the heating element and liquid water is the same as the k for the heating element and water that is undergoing a phase transition to steam. Someone who remembers their college thermodynamics a lot better than I do will be needed here. Second, the battery is going to have some limit on how fast it can transfer energy. That may be low enough that whether you use one drum or multiple may not matter.