The watt usage rating refers to the number of watt-hours or kilowatt-hours that an appliance uses. Watt-hours are calculated by multiplying the number of watts that device consumes by the number of hours it is on.
The watt-usage of a refrigerator increases as the outside temperature increases. The motor of the refrigerator must be on for longer periods to keep the refrigerator colder, because more energy is required to keep the refrigerator colder in warmer temperatures.
The watt-usage rating is higher immediately after an appliance with a motor is turned on than when the motor has been operating for a few seconds. The amount of power required to make a motor turn initially, called the surge power, is higher than the power to keep it turning. This is due to the inertia of the motor.
The watt-usage rating for a clothes dryer is one of the highest of all appliances. A clothes dryer can require up to 5000 watts to operate. This is much higher than a refrigerator or microwave. One hour of dryer time can consume as much energy as 10 hours of refrigerator time.
The watt rating of an electric hair dryer is very high considering its size. Electric hair dryers have watt ratings in the order of 1,000 watts, higher than most refrigerators. This means your hair dryer consumes more energy when it's on than your refrigerator does.