Reducing Noise from Hand dryers in your workplace
Whether you are in a restaurant, school, office, or factory, unwanted noise can be, at best, distracting, and at worst, a health and safety hazard. Taking steps to reduce the amount of excess noise in a building is important. Loud noises from old fashioned warm air hand dryers in bathrooms can easily escape into the surroundings, and disturb people.
What causes Hand Dryer Noise
Conventional hand dryers cause unwanted noise in several ways. The majority of noise is created by the turbulent airflow from the nozzle, and there is additional noise from the fan and motor assembly.
The way a warm air hand dryer works relies on hot air being blown unevenly over the users hands. The turbulence of the airflow helps to create conditions that allow water to evaporate and be carried away from the skin. However, this turbulent air creates noise across a wide frequency spectrum that can be very loud. Traditional hand dryers operate at a level around 85dB because of their design. This is the noise equivalent of heavy traffic heard from the side of a busy road!
Modern jet hand dryers such as the Mitsubishi Electric Wave u02 use a high speed jet of cleanly flowing air to blow water off the skin surface. This means that there are fewer competing frequencies and less harmonic distortion in the sound, and as a result, the amount of noise is reduced significantly to around 57dB – about the level you would experience in a normal conversation.