Acoustic

Noise Analysis：

The main source of noise generated by Shanghai Tower after the construction: surrounding vehicle noise; noise of air conditioner operation; the noise of underground wind exhaust fan; noise in distribution substation generated; water pump and heat pump running noise under operation; cooling tower heat pump unit running noise; running noise of diesel generator system.

Indoor acoustic environment:

1.The design of Ultra-Silent Air Handling Units:

In order to meet the required building’s energy efficiency quota, many interventions occurred. For instance, Shanghai Tower maximizes utilization ratios of architectural space and indoor story heights, and all air VAV conditioning system. Since, the indoor noise is required to be less than 45 decibels, noise elimination equipment is installed in the machine room and air blasé ducts, by and large, the aforementioned measures still fail to meet the requirements of noise elimination. Thus, in the stage of equipment tendering, a highly rigorous test requirement for the noise of floor air handling unites and air conditioning facilities put into the design process. Also, engineer instated a more severe manufacturing requirement on the boundary dimensions of air conditioning units in order to meet the needs for air conditioning room spaces.

In the stage of design bidding, designer evaluated noise levels of the units by testing the prototype’s noise spectrum eight times according to the noise evaluation standard Nc40 values. In the end, the noise of the ultra-silent air handing units adopted by this tower has been reduced so substantially that they produce no more than 15 db (A).

2. Sound level requirement on Cooling-Heating-Power Supply System:

Another requirement for a combined cooling and heating power system in the project is the damping and noise reduction. Now, the noise of the machine room that is set by system equipment reaches to less that 78 db (A) while the noise of outside the room and control room reaches to less than 60 db (A). The noise levels now meet and exceed the technical specifications of the owner.

3. indoor greenery:

The greenery of elevation-based gardens in atrium also is integrated to a vertical system based on natural vegetation. A great amount of reserches proved that leaf of plants having good abiity to absorb sound and becoming nice sound reflector. So, exterior greenery can relatively perfect acoustic environment to buiding.

Measures for protection of the acoustic environment during building operation period:

The cooling tower of Shanghai Tower will come about a certain influence to the position near the top of the podium, recommended to set the location away from the boundary beyond 50m; or take insulation maintenance measures to reach the requirement on the podium’s boundary.

The premise of acoustic environment protection under some appropriate measurements of Shanghai Tower, adopting low noise equipment; taking control measures to the external environment that unaffected to surroundings. The road traffic noise environmental noises outside the building project exceed the standard (daytime, night 1~6dB (A) 1~8dB (A)), but after the insulation of glass curtain wall, noise level of the office and hotel department can meet the design requirements.