As people’s awareness of hygiene continues to increase, most people will dry their hands in time after washing their hands, such as using tissue, towels, hand dryers, etc. to dry their hands. However, the production of tissue, towels will destroy the environment and cause ecological damage. People realize the importance of protecting the environment and gradually choose not to use tissue and towels as the first choice for hand drying. Instead, hand dryers are the more environmentally friendly option to dry hands.
Early hand dryers made unpleasant noises when they were in operation. Especially in public places, it will cause noise disturbance to nearby people. According to related reports, long-term noise pollution can damage people’s nerves. In order to protect people’s health, the research and development personnel have mute the hand dryer from different aspects.
The decibel level is a very unreliable guide for explainers. The noise level varies depending on the sound at its location, and most manufacturers’ tests are performed in an echoless (soundproof room), so no additional noise is generated. In practical use, any sound of approximately 68-78 dB (A) represents a low-decibel hand dryer.
What is hand dryer?
Hand dryer is a kind of sanitary ware used in bathroom to dry hands with hot air or hand dryer with strong wind. It can be divided into induction type automatic hand dryer and manual trigger type hand dryer. It is widely used in hotels, restaurants, scientific research institutions, hospitals, entertainment venues and other public places.
Generally, the noise of jet hand dryers which with strong wind and heating as supplementary is relatively large, while the noise of hot-air dryers as the mainstay is relatively small.
- PTC heating
The PTC thermistor will change with the change of the ambient temperature. In winter, the PTC heating power increases, and the temperature of the warm air blown by the hand dryer is stable, which is energy-saving and environmentally friendly. Although PTC is characterized by good temperature constancy, it also has certain shortcomings. PTC thermistor does not increase the temperature of the heating wire as quickly.
- Electric heating wire heating
The traditional heating wire heating, the wind temperature rises quickly, but the wind temperature stability is poor, the wind temperature is higher after a period of operation, it will burn the user’s hand. Usually need to add thermal protection device.
The main cause of noise
The electric motor is one of the core components of the automatic induction high-speed hand dryer, and it is also the main equipment for noise generation. The air is compressed by the electric motor to accelerate the processing to form a high-speed airflow. The airflow makes a harsh noise as it passes through the channels inside the machine. This is also the main reason for the noise of the hand dryer.
How to reduce noise
Therefore, product designers try to design the airflow channel as simple as possible, the inner wall is smooth, and the outer periphery is equipped with sound insulation cotton to isolate the noise as much as possible.
In addition, hand dryers driven by capacitor asynchronous motors, shaded pole motors, and DC motors generate less noise.