Acoustic enclosures and sound barrier walls both use materials designed to reduce noise, but their material compositions and construction approaches differ according to their specific applications and performance requirements.
Materials Used in Acoustic Enclosures
- Metals for Outer Shell: Acoustic enclosures typically use durable metal casings such as pre-galvanized sheet steel, precoated/colored steel, stainless steel (Types 304 and 316), aluminum, and aluminized steel. These metals form an outer and inner shell that encapsulates the sound-absorbing materials.
- Sound Absorbing Media: Inside the metal shell, the enclosures contain layers of absorptive acoustic media like mineral wool or long-strand fiberglass. This media is odorless, rot-proof, mildew resistant, non-hygroscopic, vermin-proof, and does not support fungal growth. The acoustic media is often protected by a perforated steel sheet and faced with a glass fiber scrim to enhance durability and sound absorption.
- Panel Construction: The panels can be solid or perforated, with typical gauges being 16 to 18 gauge for outer shells and 22 gauge for perforated inner shells. The insulation is compressed to prevent settling and maintain acoustic performance.
- Additional Features: Acoustic enclosures often meet fire safety standards like NFPA-90A, with low flame spread and smoke developed ratings. They may also have thermal insulation properties.
Materials Used in Sound Barrier Walls (General Overview)
While specific details on sound barrier wall materials are not provided in the search results, typical sound barrier walls often use:
- Mass Materials: Heavy, dense materials such as concrete, masonry, or earth-filled panels are standard to block sound transmission primarily through mass.
- Sound Absorptive Materials: Sometimes barriers incorporate absorptive layers such as mineral wool or specialized acoustic foams to reduce sound reflection off the barrier surface.
- Finishes and Coatings: Barrier walls may be coated for weather resistance and durability but generally do not require the fully enclosed metal shells seen in acoustic enclosures.
Comparison
| Feature | Acoustic Enclosures | Sound Barrier Walls |
|---|---|---|
| Outer Shell Material | Metals: galvanized steel, stainless steel, aluminum | Dense materials: concrete, masonry, composite panels |
| Inner Acoustic Material | Mineral wool or fiberglass with protective scrim | Often mineral wool or acoustic foam layers (if any) |
| Construction | Enclosed panels with perforated and solid metal shells | Massive, typically solid walls without enclosure |
| Additional Properties | Fire resistant, vermin-proof, rot-proof, thermal insulation | Primarily mass for sound blocking; may include absorptive layers |
| Applications | Enclose machinery or noise sources for targeted noise control | Outdoor noise barriers along highways, railways for broad noise screening |
Summary
Acoustic enclosures use specialized metal shells combined with absorptive mineral wool or fiberglass media inside to absorb and contain noise from equipment or machinery within a compact, controlled volume. Sound barrier walls rely more on mass and sometimes absorptive materials but do not typically have the enclosed metal construction. Enclosures emphasize absorption and isolation with fire and vermin-resistant media, while barriers focus on blocking and reflecting sound on a larger scale. The materials for enclosures prioritize durability, acoustic absorption, and fire safety, whereas sound barrier walls prioritize mass and weather resistance. This reflects their different noise control roles and installation environments.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-the-materials-used-in-acoustic-enclosures-compare-to-those-in-sound-barrier-walls/
