Stack insert silencers are designed to be installed inside vertical discharge stacks, exhaust ducts, or breeching outlets to reduce airborne noise from engines, blowers, and high-velocity process systems. These silencers offer effective broadband and tonal noise control with minimal pressure drop and are ideal for applications where space or structural constraints prevent the use of external silencer housings.

Stack silencers are typically circular and come in a range of internal configurations, including parallel baffle, annular ring, and straight- through designs. Constructed from durable steel and fitted with acoustic media protected by perforated liners, they are custom- fabricated to match stack diameter, insertion depth, acoustic performance, and airflow parameters.

Key Features

Efficient Stack-Mounted Noise Reduction

Installs directly inside the discharge stack—ideal for vertical exhaust or confined-space applications.

Multiple Acoustic Configurations

Straight-through circular silencers with axial airflow

Parallel baffle silencers for higher insertion loss and turbulent flow Annular ring silencers with central airflow path and radial attenuation Absorptive Acoustic Design

Uses high-performance insulation to dissipate noise energy while

maintaining airflow velocity.

Custom-Fabricated to Fit Stack Geometry

Diameter, length, support structure, and mounting interfaces tailored to your stack or duct design.

All-Welded, Weather-Resistant Construction

Fabricated from galvanized or stainless steel with optional high-temp

finishes for exposed exhaust use.

Typical Applications

Vertical discharge stacks for engines, generators, or blowers Process exhaust systems in industrial or power generation facilities Rooftop exhaust plenums or duct risers

Retrofit projects with stack noise issues and no room for external silencers

Acoustic upgrades in confined or weight-sensitive environments

Performance by Design

Stack insert silencers are engineered to provide targeted insertion loss while maintaining stack performance. Selection of the silencer model depends on airflow velocity, available length, acoustic spectrum, and space constraints. Each unit is sized to provide optimal attenuation across key frequency bands while minimizing pressure drop.

Design factors include:

Stack diameter, flow rate, and velocity profile

Target frequency spectrum and required insertion loss Maximum allowable pressure drop

Environmental exposure (rain caps, wind loading, temperature) Internal vs. external mounting hardware or slip-fit requirements

These silencers offer a compact, effective, and structurally efficient solution for reducing vertical discharge noise—ensuring compliance and comfort without major stack modifications.