When does the noise dream stop

——Discussion on the solution of "elevator noise"

The picture shows the elevator maintenance personnel looking for noise solutions.

    Our reporter Xu Jianhua

Today, the house has become the most important economic expenditure for families. If you buy a house with elevator noise, your life will be greatly affected.

The problem is that the appearance of elevator noise is often after the elevator in the building is put into use for a period of time. Because only when the occupancy rate of the building is higher and the frequency of elevator is higher and higher, the harm and influence of elevator noise will be more obvious. But often at this time, the building structure of the building has been unable to change. Therefore, the control of elevator noise has become a measure of "mending the past".

Awkward elevator noise reduction industry

With the rapid development of real estate in China, elevator has become an indispensable tool in people's life. In a short period of more than ten years, China's elevator industry has experienced the transformation of AC double speed, AC speed regulation, frequency conversion speed regulation, frequency modulation and voltage regulation, inorganic room and permanent magnet synchronous technology. It took more than 100 years to complete the development process in foreign countries, and only 30 years in China.

"It is this rapid development that makes the elevator noise problem very common in the current real estate. In the case that the building structure cannot be changed, the noise source control becomes the only way to solve it. " "The noise reduction of elevator noise is a marginal industry across the elevator and environmental protection industries," said Ma Denghua, chief designer of elevator noise reduction of shenri mechanical and Electrical Equipment Co., Ltd

Input "elevator noise reduction" on the Internet for search, and found that many enterprises claim to be professional elevator noise (noise) management enterprises, which can provide professional elevator noise reduction treatment. Elevator noise treatment has become an embarrassing sunrise industry. Generally speaking, from the cost point of view, elevator manufacturers will not have a lot of investment in this area, because after all, elevator noise is also affected by many other factors, so architectural design becomes the key.

"At present, the solution to the problem of elevator noise in civil buildings has been paid attention to. Major universities all over the country have begun to study architectural acoustics. In the past, architectural acoustics mainly studied the architectural acoustics of theater and auditorium. Now, special research has been carried out to solve the noise problems of civil buildings, including the elevator noise disturbing the residents, with mature results. I believe that in the future architectural design, there will be a single design of elevator sound insulation. " Zhang Zhaoyi, deputy chief engineer of Tianjin architectural design institute, said.

Noise standards still need to be improved

It is understood that the elevator noise is not the same as the noise in daily life. It belongs to low-frequency noise, that is, the frequency is below 500 Hz. Low frequency noise is different from high frequency noise. High frequency noise can rapidly attenuate with the distance or when encountering obstacles; low frequency noise decreases very slowly, and the sound wave is longer, so it can easily pass through obstacles.

Experts say that low-frequency noise is a kind of chronic damage to the human body, which is easy to make people fidgety, irritable, and even irrational. If disturbed for a long time, it may also cause neurasthenia, insomnia and other neurosis, and even affect the development of the fetus in the womb of pregnant women. In an interview with the media, Dou Yansheng, director of the environmental impact assessment office of China CDC, pointed out that although the impact of low-frequency noise on physiology is not as obvious as that of high-frequency noise, it can reach directly to the human ear bones, make people's sympathetic nerves tense, cause tachycardia, blood pressure rise, and internal secretion disorder.

"Low frequency noise is transmitted through the structure, so it is easy to cause people's feeling resonance. Generally speaking, people's tolerance to low-frequency noise is relatively low. Under normal circumstances, 30 to 35 decibels can be accepted by ordinary people, and people above 35 decibels will feel uncomfortable. " An expert from Tsinghua environmental monitoring center told reporters.

It is reported that at present, there are three kinds of standards related to elevator noise: first, the quality standards of elevator itself, mainly including technical conditions of elevator, safety code for elevator manufacturing and installation, etc.; second, the architectural standards, mainly including code for residential design and code for sound insulation design of civil buildings; third, the environmental protection standards, mainly including acoustic environment quality Measurement standard, etc. These three standards also have different regulations on the limit value of elevator operating decibels: the product standard stipulates that the sound of the main engine room shall not be higher than 80 decibels, the sound of the car shall not be higher than 55 decibels; the architectural design standard stipulates that the sound shall not be higher than 50 decibels in the daytime and 40 decibels at night; the environmental protection standard stipulates that the sound shall not be higher than 40 decibels in the daytime and 30 decibels at night.

"The main debate now focuses on the environmental protection standard and architectural design standard. The construction standard is the A-level standard for stable noise, and it is also the regulation 21 years ago. For the first time, the environmental protection standard provides detailed evaluation indexes for the low-frequency noise caused by the indoor noise of fixed equipment for structural transmission, which makes up for the lack of low-frequency noise standard in China and more conforms to the reality of the society. It should be said that it's time to revise the elevator noise standard of the construction department. " Said Qing Zhengke, a lawyer at Beijing Guangsheng law firm.

According to Ma Denghua, the provisions in the architectural design standard that "elevator shaft cannot be installed next to the bedroom, but if it is inevitable in design, noise reduction measures should be taken" provide negative support for the hidden danger of elevator noise from the beginning of architectural design. Considering the actual situation, relevant standards should be modified. China Quality News