Like most home appliances, the hair dryer runs on a motor. The motor, which is powered by electricity, makes the fan spin. This mechanism allows room temperature air to be sucked in through the vents of the hairdryer and then to be blown over the heating coils. The air is heated and forced out of the head of the hair dryer towards the hair.

There are 2 types of motor available in the market – AC and DC. Hair dryers with AC motor are widely used by hair care professionals, whereas those with DC motor are ideal for home use. AC motors are larger and more powerful, will last up to 1,200 hours, and operate at a maximum speed of 6,000 revolutions per minute (rpm). On the other hand, DC motors are lighter, will last no more than 700 hours, and have a speed of up to 2,000 rpm.

The table below lists the differences between AC and DC motors:

Features	AC Motor	DC Motor
Current Flow	Alternate	Direct
Weight of Motor	Heavy	Light
Life Expectancy	700-1,200 hours	400-700 hours
Speed	5,000-6,000 rpm	1,500-2,000 rpm
Airflow	Powerful	Not so powerful
Sound	Quiet	Noisy
Ideal for	Salons	Home Use

Hair dryers that run on AC universal motor can achieve high-speed blow drying while operating on a single-phase power supply. The downside of a universal motor, however, is that the hairdryer tends to be larger, heavier and noisier. A motor manufacturer and supplier, Nidec Corporation, identified the need for compact, light and energy-efficient hair dryers. To meet this need, the company developed an integrated motor called the brushless DC motor for hair dryer manufacturers. With integrated AC-DC power supply circuits, this motor is half the weight of a universal motor, 25% faster, and will last 10 times longer.

The power and speed of a hair dryer, which are primary considerations in the average consumer’s purchase decision, depend largely on the wattage of the motor. Wattage measures how fast the motor of the hair dryer will spin to produce warm air. A good hair dryer has a strong motor which will dry hair fast without damaging the hair with excessive heat.

A motor with a high wattage will optimize hair dryer performance in terms of speed and airflow. High wattage means greater speed, stronger airflow, and more heat. In other words, the higher the wattage of the motor, the hotter and faster the hair dryer. Apart from boosting wind power and reducing styling time, a motor with high wattage has the added advantage of not burning out as quickly as a motor with low wattage.

A motor of 1,500 watts is ideal for home use. One with 1,875 watts will give you faster drying and styling. It is important to note, however, that the higher the wattage of the motor, the heavier the hair dryer. If you travel often, it is advisable to carry a light hair dryer – one that does not weigh more than 1 lb. This means you must choose a hair dryer that has a motor with low wattage – somewhere in the range of 1,200 watts. If you have long hair, it is better to choose a hair dryer that is easier to carry. It takes longer to dry long hair and a light hair dryer will not give you arm fatigue. Therefore, you should buy a hair dryer that runs on a motor of low wattage.

If you want to save on electricity, then you should opt for a hairdryer that uses a low wattage motor. High wattage means high electricity consumption and therefore a high electricity bill.

Your hair type will also determine whether a high or low wattage is appropriate. If you have thick hair, a hair dryer in the range of 1,600 and 2,000 watts is recommended. For thick and curly hair, a 2,000-watt hair dryer is perfect. People with thin hair require lower wattage – somewhere in the range of 1,200 and 1,500 watts. Wattage higher than this will damage thin hair.

China, Korea, and Italy are well-known makers of hair dryer motors. Italy manufactures titanium AC motors for professional grade hair dryers of 2,200 watts and above. Hong Kong’s Johnson Electric Group added two new models of hair dryer motor to its product line. Model U5413-L weighs 225 grams, has a lifespan of 1,000 hours and a power of 1,875 watts. Model U5413-P weighs 250 grams, has a lifespan of 1,200 hours and a power of 2,000 watts.

Apart from wattage and place of origin, hair dryer motor specifications include speed, torque, voltage, certification, efficiency, shaft diameter, frequency, phase, and output power. With an increasing demand for faster and lighter hair dryers, manufacturers must select motors with the most favorable combination of specifications.

Sources

Electrical Engineering, How does a hair dryer change its motor speed? Diagram included
Mitch, Hair Dryer Fan/ Motor Assembly Replacement