To calculate the change in temperature, subtract the initial temperature from the final temperature. Example: 84.2 degree Fahrenheit - 41 degrees Fahrenheit = 43.2 degrees Fahrenheit. The temperature from morning to afternoon changed by 43.2 degrees Fahrenheit.
It needs 12 volts so it will be the standard modern power supply provides 12 volts of power.
For a normal, single-phase power supply at 240 volts, the maximum current would be 100 amps. The current in amps multiplied by voltage in volts gives power in watts (Power = voltage x current). If a three-phase supply is available, then the 24,000 watts are divided by 3, meaning that 8000 watts is being used per phase.