For over 45 years Industrial Acoustics Company has been a leader in the development and application of noise control technology. Since 1949 IAC has designed and installed thousands of noise control systems at power generating and distribution facilities worldwide.

IAC offers laboratory and field proven noise control products to satisfy guarantees and minimize owner risk. Noise control for low frequencies can be a critical issue in obtaining regulatory and community acceptance.

This guide illustrates common noise sources typical to power generation facilities and indicates the noise attenuating devices that may be used to control them.

GAS TURBINES-Low and High Frequency Noise Controlled with Power-Flow® Silencers
Complete IAC noise control systems including Power-Flow® Intake and Exhaust Silencers and Noishield Enclosures are available to reduce gas turbine noise. Power-Flow Silencers may include dissipative and/or reactive elements to provide the most cost-effective means of satisfying applicable noise criteria. IAC has designed and manufactured Power-Flow Silencers for most power generation gas turbines. Designs are available for many replacement silencers applications. IAC's proven expertise in the application of resonator technology will provide economical solutions to any special low-frequency noise problems.

STEAM TURBINES-Noise contained with Noishield® Cladding and Enclosures
Steam turbine cladding is accomplished with Moduline® Noishield Component System designed to provide high Sound Transmission Loss (STC) and Sound Absorption (NRC) performance.The modular system is engineered for fast track installation by semi skilled personnel. IAC's cladding system can be designed to allow visual inspection and maintenance of equipment with minimal disruption of service for indoor and outdoor facilities.

GENERATORS-Operate quietly within Noishield® Enclosures
Noishield enclosures, room offices and partitions can be designed to provide noise reduction performance in accordance with acoustical and space requirements. IAC designs acoustic structure in its Aero-Acoustic Laboratory to meet specific noise reduction, aerodynamic, thermodynamic, structural and mechanical requirements. If discrete low or high frequency peak noise sources are a factor, IAC can provide proven designs to attenuate them.

VENTILATION - Noise controlled with Noishield® Louvers
IAC's Louvers provide effective weather barriers together with noise control and low pressure drop for air intakes, supply systems, equipment rooms, penthouses, noise barriers, cross talk silencers, cooling towers, and others. Noishield Louvers offer decorative exteriors, color coordinated finished and corners for architectural compatibility. Supplied in galvanized steel or mill finish aluminum for field painting; options include stainless steel and laminated finishes.

Quiet - Duct Silencers, including low frequency designs, are available in more than 26 standard models in many cross - sections and lengths for a wide range of acoustic and aerodynamic criteria.

INDUCED DRAFT FANS - Control noise with ACoustic FIlter (ACFI) Silencers
ACFI Silencers are designed to attenuate blade pass and harmonic frequencies even after buildup of fly ash or other deposits. ACFI Silencers are engineered to provide broad band Dynamic Insertion Loss (DIL) and minimum pressure drop. Parallel air paths help minimize pressure drop and permit inspection and maintenance of sound absorbing cavities without splitter removal.

FORCED DRAFT FAN-Control Noise with Power-Flow® Silencers & Noishield Housings
Power Flow Silencers for forced draft and induced draft fans are designed to economically satisfy a wide range of acoustical and aerodynamic requirements: they are laboratory rated to assure specified results.
Noishield Fan Housings, constructed of IAC Moduline acoustically rated and field tested components, are manufactured with corrosion resistant material for long life essential to power plant operations.

TRANSFORMERS-Hum contained inside Moduline Noishield® Enclosures or Barrier Walls
Transformers are often one of the most difficult noise problems to control. Due to the general predominance of transformer "hum" and cooling fan noise at 100 or 120 Hz, transformers require noise barriers highly rated for transmission loss and sound absorption at these frequencies. Moduline Enclosures and Noishield Barriers are rated from STC 40 to STC 70 (special designs available) and at NRC 0.95 to absorb incident sound.
Enclosures and Barriers can be built to meet dimensional and noise reduction requirements. Constructed of galvanized or stainless steel, the systems can be readily remounted for transformer maintenance. Noishield barriers break the noise source line of sight and improve plant appearance.