A Govt. Of India Initiative To Curb Noise Pollution

One of the largest public sector entity of Government of India had constructed a large multipurpose hall in one of their staff colony in the year 1999. Multipurpose halls are basically used for recreation, indoor games and cultural functions with amplifying sound systems.

Couple of days prior to the inauguration of the hall, it was found that there was enhanced echo due to multiple sound reflections which highly impaired the clarity of speech. The chairman for the organization took the decision to rectify the flaw and ensure the hall’s efficient functioning.

Thermosonics Private Limited was invited to study the case and provide them with effective solution to fulfil all the requirements of the multipurpose hall as per building codes & standards.

A primary study revealed that multiple reflection of sound caused overlap of words, resulting in loss of clarity of speech. Thermosonics carried out RT 60 test of the hall to assess the reverberation time. To reduce reverberation time to acceptable level, a design was prepared using necessary acoustical material. The final report was simulated and submitted to the customer for their perusal.

Customer approved the design and placed the order to rectify this aberration. RT 60 was once again conducted post execution of work and found that it complied with the international standards of acoustic ambience of multipurpose hall. On completion of work, a letter of appreciation was sent by the customer accepting the solution as an effective one.

Noise Dispute Redressal Between A Banking Conglomerate & A High End Residential Complex

A multinational bank set up its back office at a prime location in Mumbai. As back-up power for the office, they installed three 1010 KVA Diesel Generator sets. The office is situated in a large commercial complex where several other buildings in the premises also housed offices having their own back-up generators.

The bank was in a declared commercial zone but was sharing a common compound wall with a residential complex. During commissioning of the generators, the noise was too loud and objectionable to the occupants of neighboring complex. They complained to the State Pollution Control Board (SPCB) which is the state authority that presides over such matters, who in turn instructed the multinational bank to reduced noise with immediate effect and deferred the bank from running their power generators at night till noise norms were complied with.

Thermosonics Private Limited was invited to study the case and propose a method to reduce noise and comply with norms as per SPCB. The analysis showed that the power generators were meeting requirements of noise norms of Industrial Zone, however they were installed right adjacent to a residential zone. The matter became further complicated as the 24×7 backup office could not be used by the bank, due to the restrictions imposed, in case of power failure. Detailed study revealed that as there were multiple generators within the commercial complex apart from the client’s unit, it was necessary to ensure that the noise levels were brought down below SPCB prescribed norms for residential zones.

Another issue was the exhaust gas from power generators that was built at a height of 7 meters from ground was also objectionable to the members of the residential complex. They feared that changing wind direction could sweep the flue gas towards them.

The following solutions were proposed by TPL with guaranteed attainable results: –

• A secondary modular acoustic enclosure with adequate forced ventilation installed enclosing all 3 power generators within.
• Exhaust gas ducts are taken to a height above the 11 storied residential complex.
• Pre and post acoustic installation, sound pressure level at residential complex to be measured in the presence of SPCB officials with their instruments to establish compliance.

The Bank was convinced with this approach and placed an order with Thermosonics Private Limited to execute the job within stipulated time. Noise measurements were taken in the presence of the officials from SPCB, the bank representatives and members of residential complex. The results were found acceptable to the SPCB officials as well as the residents of the complex. Following which a MOU document was prepared and signed by all officials to safeguard the bank from any future complaints from neighbors.