240v lets you pump more amps through smaller gauge wire, but since it’s an air fryer only needs to maintain a certain temperature, 120v is fine, and will not use any additional power over 240v. The amount of total watt hours used is what determines efficiency.
Where 240v is nice is with electric water kettles, where the higher voltage increases your wattage ceiling, letting you dump the energy into the water faster, and thus boiling it faster. A 120v electric kettle would use the same amount of total watt hours to boil the water, but because it’s heating it with a lower wattage output, it just takes longer.
240v lets you pump more amps through smaller gauge wire, but since it’s an air fryer only needs to maintain a certain temperature, 120v is fine, and will not use any additional power over 240v. The amount of total watt hours used is what determines efficiency.
Where 240v is nice is with electric water kettles, where the higher voltage increases your wattage ceiling, letting you dump the energy into the water faster, and thus boiling it faster. A 120v electric kettle would use the same amount of total watt hours to boil the water, but because it’s heating it with a lower wattage output, it just takes longer.
Technology Connections did a good video on the subject.