2007 Standard for Reverberation Room Qualification and Testing Procedures for Determining Sound Power of HVAC Equipment

ARI Standard 220: 2007 Standard for Reverberation Room Qualification and Testing Procedures for Determining Sound Power of HVAC Equipment

In the demanding field of HVAC engineering, accurate sound power determination is not merely a technical detail; it's a critical factor influencing product design, regulatory compliance, and occupant comfort. ARI Standard 220: 2007 provides the essential framework for achieving this precision, offering engineers and manufacturers a proven method for qualifying reverberation rooms and reliably measuring the sound power of HVAC equipment.

What is ARI Standard 220?

ARI Standard 220: 2007, developed by the Air-Conditioning and Refrigeration Institute (ARI), establishes a comprehensive methodology for determining sound power levels of HVAC equipment using reverberation rooms. It mandates pre-qualification of the test environment and specifies the use of the Comparison Method, an industry-leading technique for ensuring accuracy and repeatability in acoustic measurements.

Scope & Purpose

This authoritative standard governs the qualification of reverberation rooms for acoustic testing and prescribes the procedures for measuring the sound power of HVAC equipment that emits broadband, discrete-frequency, or narrow-band noise. It specifically details the physical environment, testing procedures, and instrumentation required for these measurements. The standard is applicable to HVAC products tested within a reverberation room that meets its stringent qualification criteria, focusing on obtaining results with acceptable accuracy and reproducibility.

Who Must Comply?

• • Primary audience: Acoustic Engineers, HVAC Engineers, Test Engineers, Product Development Engineers, and Laboratory Technicians involved in HVAC equipment noise assessment.
• • Industries affected: HVAC Manufacturing, Building Construction, Acoustics Consulting, and Product Testing Laboratories.
• • Compliance nature: This is a voluntary industry standard, recommended for ensuring product quality and accurate performance data.
• • Enforcement: While not legally mandated, compliance is often a requirement for product certification, industry recognition, and to meet contractual or design specifications.

Key Requirements Overview

• • The standard requires rigorous pre-qualification of reverberation rooms through specific tests to ensure they provide an acoustically suitable environment for accurate sound power measurements.
• • Professionals must employ the Comparison Method, which involves comparing the sound pressure levels of the equipment under test to those of a calibrated Reference Sound Source (RSS).
• • Key provisions include detailed guidelines for instrumentation, installation, and operation of sound sources, as well as procedures for determining optimal microphone positions or traverse lengths.
• • The standard outlines specific calculation procedures for determining Sound Power Levels in one-third octave bands, ensuring detailed spectral analysis.
• • It also specifies limits for standard deviations of sound power level reproducibility to ensure consistent and reliable results across different test conditions and laboratories.

Related Standards & References

ARI Standard 220: 2007 works in conjunction with other critical standards to provide a complete acoustic testing framework. It references ANSI S12.51/ISO 3741 as a foundational document, building upon it with more specific requirements for HVAC applications. Crucially, it relies on ARI Standard 250 for the accurate calibration of the Reference Sound Source (RSS), which is fundamental to the Comparison Method. Integration with these complementary standards ensures a robust and reliable approach to HVAC equipment acoustic performance evaluation.