Electrically heated hand dryers function by using electrical energy to generate heat and airflow to dry hands. Here's a general overview of how they work:
Air Intake: When a user places their wet hands under the dryer, the device's sensor or button is activated, initiating the drying process. The dryer has an intake mechanism that draws in air from the surrounding environment.
Heating Element: Inside the hand dryer, there is a heating element, usually made of a resistant material like nichrome wire. When the heating element is turned on, it starts to heat up rapidly due to its resistance to the electric current passing through it. This heated element is the key component that warms the air before it's blown onto the user's hands.
Airflow System: The heating element is typically located between the fan and the air outlet. As the heating element heats up, the fan draws in ambient air from the intake and forces it over the heated element. The air gets heated as it passes over the element, reaching a higher temperature.
Warm Air Blowing: The heated air is then blown out of the dryer's nozzle onto the user's wet hands. The combination of warm air and the airflow help to evaporate the moisture on the hands, gradually drying them.
Moisture Evaporation: The warm air increases the rate of evaporation of the water on the hands, which leads to drying. The higher temperature of the air helps to carry away the moisture from the skin's surface more effectively.
Automatic Shutoff: Many modern hand dryers come equipped with sensors that detect when the user's hands are removed. Once the sensor no longer detects the hands, the dryer automatically turns off to conserve energy.
It's important to note that while electric hand dryers are generally considered more environmentally friendly than paper towels (as they reduce paper waste), they do consume electricity. The efficiency of the drying process can vary depending on the design and quality of the hand dryer. Some models are more effective than others at quickly and thoroughly drying hands.
Overall, the combination of a heating element, a fan, and an airflow system is what allows electrically heated hand dryers to efficiently dry hands using warm air.