Sound isolation of a generator in Telenor

Project Overview

Telenor, located near Business Park Sofia, operates a large data centre requiring powerful cooling systems. To ensure uninterrupted power, the company relies on two diesel generators, each the size of a ship's engine, for backup electricity. While these generators are rarely activated, when they do operate—sometimes during the night for several hours—their noise has been a source of significant disturbance for nearby residents. The problem escalated to the point where a frustrated neighbour fired an air rifle at a Telenor employee in protest of the noise, prompting urgent action from the company.

Challenge

The noise generated by the diesel generators made it nearly impossible for nearby residents to sleep or open their windows. The issue persisted for about three years, during which residents lodged multiple complaints. Telenor sought a solution that would comply with Bulgarian noise standards for both day and night and, more importantly, restore peace to the neighbourhood.

Scope of Work

• Conduct noise measurements to evaluate the impact of the diesel generators on the surrounding residential area
• Design, manufacture, and install outdoor silencers to reduce noise levels
• Ensure compliance with both daytime and nighttime noise regulations

Solution

DECIBEL’s engineering team took on the challenge by designing and producing custom outdoor silencers for the generators. The design process, which took approximately three months, resulted in silencers weighing over 2000 kg in total. The installation of these heavy-duty silencers took 20 days under careful supervision.

The solution involved not only meeting Telenor’s contractual obligation to comply with national noise regulations but also restoring a peaceful living environment for the neighbouring residents. The silencers were designed to significantly reduce the sound emitted by the generators, ensuring that residents could no longer hear the noise during their daily activities or while trying to sleep.

Results

After installation, professional noise measurements confirmed that the generator's sound no longer disturbed the residents, even when the cooling system was in operation. Telenor's facility could continue running its data centre without interruptions, and the residents regained the quiet environment they once had. The project was a success, and the partnership between DECIBEL, Telenor, and the affected residents demonstrated the power of sound isolation in resolving community disputes.

Importance of Soundproofing in Data Centers and Urban Areas

Soundproofing solutions are crucial for businesses that operate in urban environments, especially when high-noise equipment like diesel generators is involved. Noise complaints from neighbouring residential areas can lead to long-term disputes, legal challenges, and reputational damage. By proactively addressing noise issues, companies can maintain good relationships with the community and ensure compliance with European Union noise regulations, such as Directive 2002/49/EC, which encourages noise management in urban planning.

In Telenor’s case, a well-executed soundproofing project helped avoid further escalation of the conflict and allowed the company to maintain its operations smoothly while improving the quality of life for local residents. This project highlights the importance of consulting acoustics experts early in the design process of any facility or building to prevent similar issues from arising.