Troy Acoustics Corporation
Complete Acoustic Solutions for Data Center Construction
For Developers · Contractors · Municipalities · Corporations
Exterior Perimeter Barriers · Interior Ceiling Systems
Noise Compliance · Security · Privacy · Future Value
Proven. Certified. Built for the Long Term.
thewallsoftroy.com | 800-987-3306 | Brunswick, GA | U.S. Patent 5,661,723
The Low-Frequency Threat — Invisible, Inescapable, and Unhealthy
Data center HVAC systems generate 31.5 Hz – 250 Hz energy that travels through walls, floors, and bodies.
31.5 – 80 Hz — Infrasound Zone
Below the threshold of clear hearing but fully felt by the body. Resonates in chest cavities, ear canals, and skulls. The WHO classifies sustained exposure as a health risk causing sleep disruption, anxiety, and cardiovascular stress.
80 – 160 Hz — Chest Resonance Zone
Matches the natural resonance frequencies of the human thorax. Prolonged exposure causes fatigue, cognitive impairment, and has been linked to reduced immune response in animal studies.
160 – 250 Hz — Low Tonal Hum Zone
The frequency range most commonly reported by data center neighbors. Concrete walls reflect it rather than absorb it. Standard STC testing begins at 125 Hz — missing the worst bands entirely.
Animals are affected too. Livestock, wildlife, and companion animals in proximity to unshielded data centers show elevated stress markers, reduced reproductive rates, and behavioral disruption. Low-frequency industrial noise is not a nuisance — it is a documented biological hazard.
Walls of Troy™ Transmission Loss — Low-Frequency Range
TL26-262 Data · 31.5 Hz – 250 Hz
Walls of Troy™ Absorption — Low-Frequency Range
A26-364 Data · 31.5 Hz – 250 Hz
Low-frequency data: TL26-262 & A26-364 · Riverbank Acoustical Laboratories | Troy Acoustics Corporation
Data Center Campus Construction — Complete Troy Acoustics Solution
Data centers built without acoustic planning face permit denials, costly retrofits, community lawsuits, and worker health liability.
Troy Acoustics Corporation | troyacoustics.com | 800-987-3306
Data Center Noise Sources — Why Every Campus Needs Acoustic Planning
Primary continuous noise source. High-speed fans run 24/7, projecting 31–250 Hz drone horizontally toward adjacent properties day and night.
Diesel gensets required for redundancy. Weekly NFPA 110 load testing — consistently the #1 community complaint at data center approvals nationwide.
Rooftop AHUs and cooling tower fans direct broadband low-frequency noise horizontally toward surrounding agricultural and residential properties.
120 Hz tonal hum from power transformers. Under most state codes a −10 dB tonal penalty applies — making compliance significantly stricter.
Each 500-ton chiller generates ~90 dB(A). Adding a second identical chiller adds exactly +3 dB — making it 93 dB(A). This is because decibels are logarithmic: doubling identical noise sources always adds exactly 3 dB, never doubles the level. A typical campus with 4 chillers reaches ~96 dB(A). Add cooling towers, AHUs, and generators simultaneously and the combined plant total reaches 100–105 dB(A) — far above OSHA action levels and community limits. The low-frequency component of this noise (31–250 Hz) is the hardest to block and the most harmful to human health.
The Walls of Troy Corporation | thewallsoftroy.com | 800-987-3306
The Solution:
Walls of Troy™ Highway Sound Barrier Adapted for Data Centers
Proven on American highways. Now purpose-built for data center perimeter noise control.
U.S. Patent 5,661,723 | Since 1993
Noise Reduction Coefficient
SAA = 0.87 · Riverbank Labs A26-364
Tested 2026-07-02 · ASTM C423
Sound Transmission Class
Riverbank Labs TL26-262
Tested 2026-06-26 · ASTM E90 / E413
41 dB TL at 100 Hz · 64 dB at 4–5 kHz
Preliminary — final certification pending
Outdoor-Indoor Transmission Class
Riverbank Labs TL26-262
ASTM E1332 · Low-frequency exterior standard
STC vs. OITC — Two Ratings That Tell the Complete Story
Plain-Language Definitions for Engineers, Developers & Regulators · Riverbank Acoustical Laboratories · NVLAP 100227-0
STC measures how much a barrier reduces airborne sound passing through it, tested at frequencies from 125 Hz to 4,000 Hz — the range of human speech, music, and most mechanical equipment noise. An STC 53 rating means a 90 dB noise source on one side is reduced to approximately 37 dB on the other — near inaudibility for most people. STC was originally designed for interior construction, so it starts at 125 Hz — just above the deep industrial hum that data center equipment generates. Troy Fastlane STC 53 is among the highest ratings achieved by any modular sound wall system.
- Industry standard required by most building codes
- At STC 53: loud sounds nearly inaudible next door
- Meets or exceeds every US federal & state code
OITC was developed specifically to measure a barrier's performance against the heavy low-frequency noise that comes from outside — transportation, aircraft, and industrial equipment. Unlike STC, OITC starts at 80 Hz and mathematically weights low frequencies more heavily in the rating calculation. Data center HVAC equipment — chillers, cooling towers, compressors, generators — generates exactly this profile of low-frequency industrial drone starting at 31.5 Hz. OITC 47 is the most relevant and demanding rating for real-world data center compliance because it captures the frequency bands that travel farthest, penetrate conventional walls, and cause documented health effects in humans and animals.
- Designed for EXTERIOR low-frequency industrial noise
- Starts at 80 Hz — captures the HVAC danger zone
- The real-world data center compliance standard
Certified Acoustic Performance — 2026 Riverbank Laboratory Data
Riverbank Acoustical Laboratories · TL26-262 (STC 53 / OITC 47) · A26-364 (NRC 0.90 / SAA 0.87)
Sound Absorption Coefficient by Frequency (NRC 0.90 / SAA 0.87) — A26-364
Sound Transmission Loss by Frequency (STC 53 / OITC 47) — TL26-262
SAA = 0.87 · A26-364
Tested 2026-07-02 · Preliminary
Absorbs HVAC broadband noise
41 dB TL at 100 Hz · 64 dB at 4 kHz
TL26-262 · Tested 2026-06-26
Blocks at every code-regulated frequency
TL26-262 · ASTM E1332 · Preliminary
Low-frequency industrial noise rating
The real-world data center standard
OITC 47 — Outdoor-Indoor Transmission Class — Low-Frequency Authority
Riverbank Acoustical Laboratories TL26-262 · ASTM E1332 · NVLAP Lab Code 100227-0 · Tested 2026-06-26
OITC: Reference Noise Spectrum vs. Troy Fastlane™ TL — TL26-262
| Freq (Hz) | Ref Spec (dB) | TL (dB) |
|---|---|---|
| 80 | 103 | 36 |
| 100 | 102 | 41 |
| 125 | 101 | 43 |
| 160 | 98 | 41 |
| 200 | 97 | 42 |
| 250 | 95 | 45 |
| 315 | 94 | 43 |
| 400 | 93 | 47 |
| 500 | 93 | 50 |
| 630 | 91 | 50 |
| 800 | 90 | 48 |
| 1000 | 89 | 52 |
| 1250 | 89 | 58 |
| 1600 | 88 | 59 |
| 2000 | 88 | 59 |
| 2500 | 87 | 61 |
| 3150 | 85 | 63 |
| 4000 | 84 | 64 |
Noise Compliance — Federal & State Standards Every Data Center Must Meet
EPA · FHWA · OSHA · HUD · State Property-Line Codes · Troy System Exceeds All Limits
| Standard | Requirement | Troy Performance | Result |
|---|---|---|---|
| FHWA NAC Cat. B | 67 dB(A) Leq residential | STC 53 · NRC 0.90 53 dB TL + absorption |
Exceeds |
| HUD 24 CFR Part 51 | 45 dB(A) interior 65 dB(A) exterior |
STC 53 exterior CAC 38 + NRC 1.0 interior |
Exceeds |
| EPA Community Noise | 55 dB(A) day 45 dB(A) night (outdoor) |
OITC 47 / STC 53 25–40 dB beyond limits |
Exceeds |
| OSHA 29 CFR 1910.95 | 85 dB(A) TWA 8-hr action | CAC 38 · NRC 1.0 Cuts server hall reverb |
Exceeds |
| State Property-Line (All 50 States) |
45–80 dB by octave band Class B receiving land |
Troy TL: 41–64 dB/band NRC 0.90 + OITC 47 |
Exceeds All |
| Local Zoning / CUP | Typically 50–65 dB(A) at property boundary |
15–35 dB additional margin above limits |
Full Margin |
Data Center Interior Acoustics — Worker Safety & the Troy Ceiling Solution
USG Test CAC-181107
Maximum absorption
Stops Noise Flanking Between Rooms
CAC 38 prevents server noise from migrating through shared ceiling plenums into offices, control rooms, and adjacent IT halls.
Reduces dB(A) Exposure — OSHA Compliance
NRC 1.0 absorbs virtually all sound energy, slashing reverberation time inside server halls and lowering sustained worker exposure.
Drop-In Suspended Tile — New Build & Retrofit
1″ fiber cement panels drop into standard 15/16″ DXL exposed tee grid. 6″ mineral wool above. No structural work required.
NVLAP Lab Certified
USG Test TROYC-100118 · CAC-181107 · ASTM E1414-16 · NVLAP Lab 200132-0. Independent third-party verification.
Third-Party Certifications — Critical for Data Center Use
Confirmed October 2025, UL Solutions
- Flame Spread Index: 0
- Smoke Developed Index: 0
- Class A — highest UL fire classification
- Critical for data center campus permitting
- No toxic gases emitted under combustion
- Rating: 0 (zero growth) at 7, 14, 21 & 28 days
- Tested: Aspergillus, Penicillium, Chaetomium, Trichoderma & Aureobasidium
- 28-day controlled humidity exposure
- No degradation of acoustic performance
- 99.9999% reduction vs. S. aureus
- ≥99.9999% reduction vs. K. pneumoniae
- 7-log reduction in 24 hours contact time
- Critical for high-density equipment areas
- Approved by T. Naqvi, M.S. Microbiology
Panel Composition & Structural Specifications
60% Portland Cement · 39.5% Wood Fiber (Wood Wool) · 0.5% Sodium Silicate Binder
Zero VOC · Zero flame spread (UL723) · Insoluble in water · Non-toxic · 30+ year service life
Competitive Comparison — Sound Barrier Options for Data Centers
| Performance Criterion | Walls of Troy™ 2026 |
Concrete Wall (Reflective) |
Fiberglass Panel |
Timber / Wood |
|---|---|---|---|---|
| NRC (Sound Absorption) | ✓ 0.90 | ✗ ~0.02 | ⚠ ~0.35 | ⚠ ~0.10 |
| STC (Transmission Block) | ✓ 53 | ⚠ 45–55 | ✗ 25–35 | ✗ 20–30 |
| OITC (Low-Freq Exterior) | ✓ 47 | ⚠ ~38–45 | ✗ 18–26 | ✗ 14–22 |
| Low-Freq (31–250 Hz) Health | ✓ Absorbed | ✗ Reflected | ✗ Marginal | ✗ None |
| EPA/OSHA/State Compliant | ✓ Yes | ⚠ Reflective | ⚠ Marginal | ✗ No |
| Tonal Noise Margin (−10 dB) | ✓ Large | ✗ None | ⚠ Small | ✗ None |
| UL723 Class A Fire Rating | ✓ Yes | ✓ N/A | ⚠ Varies | ✗ Class C |
| Anti-Fungal (ASTM G21) | ✓ Yes | ✓ Inherent | ✗ No | ✗ No |
| Anti-Microbial (ASTM E2180) | ✓ Yes | ✗ No | ✗ No | ✗ No |
| Modular / Adj. Height | ✓ Yes | ✗ Difficult | ✓ Yes | ✓ Yes |
| Long-term Maintenance | ✓ Minimal | ✓ Low | ⚠ Moderate | ✗ High |
✓ Meets/Exceeds ⚠ Partial/Variable ✗ Does Not Meet | Troy data: TL26-262 / A26-364 2026
Beyond Acoustics — Security, Privacy & Long-Term Asset Value
Troy's 22′+ solid Portland cement-wood fiber panels in structural steel H-beam posts form an impenetrable perimeter. This wall cannot be breached, cut, or climbed.
Troy's solid mass-wall provides total privacy — no sight lines, no visual surveillance, no photography of equipment or operations from adjacent properties.
No adjacent property has any direct visual access to the campus. Staff movements, deliveries, and facility configurations remain completely screened.
Growth Is Inevitable
Every data center built in a 'remote' zone in the last 20 years is now surrounded by development. Low-frequency hum that was acceptable then triggers lawsuits now. Plan from day one.
Barrier Value Multiplies Over Time
When residential neighbors arrive, stricter Class A noise limits apply. The Troy wall — already installed and compliant — protects against costly retrofits and legal challenges.
Permanent Security & Privacy Infrastructure
As the campus scales, the Troy perimeter wall becomes a permanent, low-maintenance security asset protecting sensitive infrastructure from a growing surrounding population.
Property Value Protection
A fully enclosed, acoustically-treated, visually screened perimeter enhances the data center's property value. The Troy wall is a long-term investment, not a cost of construction.
The Troy Acoustics System
Complete Acoustic Solutions for Data Center Construction
For Developers · Contractors · Municipalities · Corporations · Nationwide