CASE STUDIES

Noise Dispute Redressal between a Hotel & a Pharma Manufacturing Company

In the city of Navi Mumbai, there was a budget hotel operating in a corner plot of an industrial district. During the planning stage of construction of the hotel, a noise survey was conducted to assess the environmental acoustic ambience and based on the study, possible noise control methods were implemented to provide the best comfort to guests.

Over a period of time, it was noticed that a neighbouring factory extended their manufacturing premises towards the wall they shared with the hotel premises and the activity at extended area of the factory generate high noise intermittently causing discomfort in general and guest rooms in particular.

Hotel management began exploring options of solution for the noise problem. Thermosonics Pvt Limited (TPL) was invited through a referral to sstudy and give a report on possible solutions to the problem. TPL took up the project of noise abatement and studied the noise in terms of intensity and pattern of noise generation at factory, sound propagation path and its impact at overall Hotel premises and at guest rooms of Hotel in particular. The Hotel management was under the impression that by improving the acoustic valves of openable windows of the hotel towards the said factory, the noise could be reduced. However, they has to be convinced otherwise by TPL because this solution was not a conceptually strong solution.

At the same time, TPL approached management of neighbouring factory premises to explore the possibility of reduction of noise at source itself either by change in location of noisy activity or by engineering method but the factory management was nit quite responsive to the problem faced by the hotel.

After thorough study of the situation, TPL proposed to the hotel management that designing & installing a noise barrier above the common compound wall would be the most effective & economical method of noise mitigation, not only for the guest rooms but also for the entire premises of the hotel. Hotel management were convinced by this solution and approved this project and a noise barrier designed and erected to the required height.

After the installation of noise barrier was complete, a a noise survey was conducted to assess the finall effect. The results showed a drastic reduction (15dBA reduction) in noise transmission from the factory to the hotel premises & 25dBA between the factory and guest rooms.

Satisfied with the results, hotel management assured to refer TPL as the experts on any noise related problems to their network and friends.

A Govt. of India Initiative to curb Noise Pollution

One of the largest organisations 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 day of the hall, it was found out that there is multiple reflection of sound of speech which highly impaired the speech clarity. The chairman of the organisation took decision to rectify the noise flaw of the multipurpose hall to bring it back to the purpose it was built.

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

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

Customer approved the design and placed 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

One of the multinational banks set up a back office in Mumbai city at a prime location. As back-up power for the office, they installed three 1010 KVA Diesel Generator sets. The office is in a large commercial complex where several other buildings in the premised also housed many offices having their own back-uo power generators.

The office building belonging to the bank was in a declared commercial zone but was sharing a common compound wall with a posh residential complex. During commissioning of back-up power generators, the noise was objectionable to the occupants of neighbouring residential complex. They complained to the State Pollution Control Board (SPCB) which is the state authority that presides over such matters, who in turn instructed Multinational bank to reduced noise with immediate effect and bank cannot run their power generators during night till noise norms were complied with.

Thermosonics Pvt Ltd was invited to study the case and propose a method to reduce noise and comply with noise 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 because the 24×7 backup office could not be used by the bank as per the restrictions imposed n night usage of power generators in case of grid power failure. On a thorough study, it was observed that the noise of power generators needs to be reduced to such level that its contribution at residential complex is below the permissible limit set by SPCB for residential zone.

As there are several other power generators in the commercial premises next to the power generators belonging to the bank, complaints would have still risen from residential complex even after noise abatement on power generators of the bank was implemented.

Another issue was the exhaust gas from power generators that was let into atmosphere at a height of 7 meters from ground which was also objectionable to the residential complex members because the changing wind direction swept 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 has ducts are taken to a height above the 11 storied building.
  • Pre and post acoustic installation sound pressure level at residential complex measured in the presence of SPCB officials with their instruments to establish meeting the compliance.

The Bank was convinced with this approach and placed order with TPL to execute the job within the time duration. Noise measurements were done in the presence of the officials SPCB, Bank was residential complex and the results were acceptable to the SPCB as well as the residents of the neighbouring building residences. A MOU document was prepared and signed by all officials to safeguard the bank from any future complaints from neighbours.