Worked Example: US Classroom — ANSI S12.60 Acoustic Compliance
Sabine RT60 calculation for a standard American classroom meeting ANSI S12.60-2010 requirements. Features Ecophon Focus E ceiling system with carpet flooring and supplementary wall panels.
A 194.4 m³ classroom designed to ANSI-S12-60 requires RT60 ≤ 0.6s. With Ecophon Focus E on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.28s — PASS.
Room Setup
Total surface area: 248.6 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Ecophon Focus E | 72.0 | 0.90 |
| walls-main | Painted plaster | 69.0 | 0.04 |
| walls-treatment | Fabric-wrapped panel 50mm | 22.0 | 0.80 |
| floor | Carpet (heavy) | 72.0 | 0.30 |
| windows | Double glazing 6mm | 10.0 | 0.04 |
| door | Solid timber door | 3.6 | 0.08 |
Absorption coefficients sourced from manufacturer datasheets and ISO 354 test reports. Browse the full acoustic materials database.
Step-by-Step Calculation
- 1
Room Volume
V = L × W × H = 9 × 8 × 2.7 = 194.4 m³
- 2
Total Surface Area
Stotal = 72.0 + 69.0 + 22.0 + 72.0 + 10.0 + 3.6 = 248.6 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 72.0 m² × 0.90 = 64.80 Sabins
walls-main: 69.0 m² × 0.04 = 2.76 Sabins
walls-treatment: 22.0 m² × 0.78 = 17.16 Sabins
floor: 72.0 m² × 0.14 = 10.08 Sabins
windows: 10.0 m² × 0.04 = 0.40 Sabins
door: 3.6 m² × 0.08 = 0.29 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 64.80 + 2.76 + 17.16 + 10.08 + 0.40 + 0.29 = 95.49 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 194.4 / 95.49 = 0.33s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.28s. Target: ≤ 0.6s per ANSI-S12-60. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 32.6 | 70.2 | 95.5 | 117.8 | 131.7 | 130.6 |
| RT60 (s) | 0.96 | 0.45 | 0.33 | 0.27 | 0.24 | 0.24 |
| Target (s) | — | — | 0.60 | 0.60 | 0.60 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: ANSI S12.60-2010 §5.2
ANSI S12.60-2010 specifies RT60 ≤ 0.6s for core learning spaces under 283 m³. This 194 m³ classroom comfortably meets the standard with quality ceiling tiles and carpet.
STI result: 0.75 (per IEC 60268-16:2020)
Cost Estimate
Costs are indicative and vary by region, supplier, and installation complexity. For a detailed cost breakdown, use the AcousPlan calculator.
Open the AcousPlan calculator pre-loaded with the exact room dimensions (9m × 8m × 2.7m) and RT60 target (0.6s).
Open CalculatorField Story
A school district in Texas is building a new elementary school and the architect needs to demonstrate ANSI S12.60 compliance for the state education department. The original design featured exposed ductwork and polished concrete floors — a trendy aesthetic that would have produced RT60 values exceeding 2.0 seconds. After the acoustic consultant's intervention, the design shifts to a suspended Ecophon ceiling with carpet tiles, achieving excellent speech intelligibility. The consultant's calculation becomes the compliance evidence submitted with the building permit application.
Frequently Asked Questions
What RT60 does a US Classroom — ANSI S12.60 Acoustic Compliance achieve?
With the specified materials and dimensions (9m x 8m x 2.7m, volume 194.4m3), the calculated mid-frequency RT60 is 0.28s using the Sabine equation. The target under ANSI-S12-60 is 0.6s or less. The result is a PASS.
What materials are used in this education acoustic example?
This example uses Ecophon Focus E on the ceiling (NRC 0.9), Painted plaster on the walls-main (NRC 0.04), Fabric-wrapped panel 50mm on the walls-treatment (NRC 0.8), Carpet (heavy) on the floor (NRC 0.3), Double glazing 6mm on the windows (NRC 0.04), Solid timber door on the door (NRC 0.08). The total absorption at 500 Hz is 95.5 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is $9,130 for 166 m2 of absorptive material at approximately $55/m2. Actual costs vary by region, supplier, and installation complexity.
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All calculations are advisory and based on the Sabine equation (ISO 3382-2:2008 Annex A). Results require professional verification for compliance submissions. Absorption coefficients are sourced from manufacturer datasheets and ISO 354 test reports.