Custom silencer for outdoor air conditioning noise reduction

Project Overview

In 2022, a commercial office building located on the outskirts of Sofia, Bulgaria, faced two simultaneous issues related to its newly installed exterior air conditioning system. The system, mounted on the building’s facade, generated excessive noise, and its appearance did not match the building's architectural style and colours.

Additionally, the terrace where the outdoor unit was placed had a shape similar to a horn, which unintentionally amplified the noise and directed it outward, increasing sound propagation.

To solve these problems, the client contacted DECIBEL. The solution was based on the DB AL silencer, specifically designed to reduce noise in openings where large volumes of air pass, typically for cooling or ventilation purposes.

Sound Control and Visual Integration for a Building Facade

Cooling systems often require ventilation openings that allow air to move freely, but these openings can become sources of unwanted noise. In this case, the sound was directed outward and intensified due to the structure's shape. At the same time, the client requested that the noise control system's visual appearance be aligned with the building’s design.

DECIBEL was tasked with developing a solution that would achieve acoustic performance, airflow efficiency, visual harmony, and fast delivery.

Challenge

The goal was to reduce the noise generated by the air conditioning system by at least 12 dB while ensuring minimal airflow resistance and high structural durability. The system also had to be resistant to wind loads, offer long-term colour and corrosion protection, and be produced and installed within a short timeframe.

Scope of Work

• Acoustic analysis of the noise transmission and horn-like effect of the terrace
• Selection of DB AL silencers suitable for high airflow applications
• Engineering adjustments to meet the required performance:
  • Minimum 12 dB noise reduction
  • Maximum airflow resistance of 51 Pa
  • Wind load resistance of 1.2 kN
  • Colour guarantee for 300 months (RAL standard)
  • Corrosion protection guarantee for 60 months

Solution

DECIBEL delivered and installed the DB AL silencer, which is specifically engineered for use in high-airflow systems. The product features aerodynamic internal geometry that reduces sound levels while allowing free passage of air.

In this project, the silencer was custom-fitted to the facade and manufactured with a RAL-matched colour coating that guarantees no shade variation for up to 300 months. The unit was also engineered to withstand high wind loads (1.2 kN) and corrosion, meeting all performance and visual criteria defined by the client.

The production was completed in just 4 working days, and the installation took 1 working day, ensuring minimal disruption to the building's operations.

Result

The installed DB AL silencer successfully reduced noise from the air conditioning system by 12 dB, while maintaining efficient airflow. The structure blended seamlessly with the building’s facade, solving both the acoustic and aesthetic issues.

The client received a complete solution with certified durability, noise control, airflow performance, and a fast turnaround, demonstrating the flexibility and engineering precision of DECIBEL’s products.

Need a Custom Silencer for Your Building or Ventilation System?

DECIBEL designs high-performance silencers and noise control systems for HVAC and ventilation applications. Contact us for fast, reliable, and visually integrated solutions.