Method of Testing for Room Air Diffusion

ANSI/ASHRAE Standard 113-2022: Method of Testing for Room Air Diffusion

For engineers and designers focused on occupant comfort and HVAC system efficiency, understanding and validating air diffusion performance is paramount. ANSI/ASHRAE Standard 113-2022 provides the authoritative methodology for this critical task, ensuring consistent and reliable testing of how air is distributed within occupied spaces. This industry-leading standard is essential for demonstrating the efficacy of air distribution systems and achieving optimal thermal environments.

What is ANSI/ASHRAE Standard 113-2022?

ANSI/ASHRAE Standard 113-2022, "Method of Testing for Room Air Diffusion," establishes a comprehensive and repeatable procedure for evaluating the steady-state performance of air distribution systems within the occupied zones of buildings. Developed by ASHRAE, this standard's primary purpose is to provide a uniform approach for measuring air velocity and temperature distributions under specified heating or cooling conditions, ensuring accurate assessment of how air diffusers and systems perform in real-world scenarios.

Scope & Purpose

This standard governs the equipment, procedures, and measurement techniques for evaluating air speed and temperature within the occupied zones of building spaces. It is applicable to both actual and mock-up spaces, whether furnished or unfurnished, and can be applied with or without occupants present. The standard outlines requirements for instrumentation, test conditions, measurement locations, and reporting of results, focusing specifically on the steady-state performance of air distribution systems. It does not extend to transient conditions or the overall energy performance of the HVAC system beyond its impact on air diffusion.

Who Must Comply?

• • Primary audience: HVAC Engineers, Mechanical Designers, Test Engineers, Building Performance Analysts, and Facilities Managers.
• • Industries affected: Building Construction, HVAC Manufacturing, Building Services, Consulting Engineering, and Facilities Management.
• • Compliance nature: Voluntary, but often specified in design documents, performance contracts, and product certifications.
• • Enforcement: Typically enforced through contractual agreements, product testing requirements by manufacturers, and as a basis for performance verification by design professionals or commissioning agents.

Key Requirements Overview

The standard requires the use of calibrated instruments for accurate measurement of air velocity and temperature. Professionals must ensure that test conditions, including room temperature and air flow rates, are precisely controlled and documented according to the standard's specifications. Key provisions include defining specific measurement locations within the occupied zone and establishing clear criteria for reporting test results, which often involve calculating metrics like air diffusion performance index (ADPI). The standard emphasizes repeatability, ensuring that tests conducted at different times or by different parties can yield comparable results.

Related Standards & References

ANSI/ASHRAE Standard 113-2022 often works in conjunction with other ASHRAE standards that address broader aspects of HVAC design and performance. For example, ASHRAE Standard 55 (Thermal Environmental Conditions for Human Occupancy) provides the fundamental criteria for comfort that the diffusion performance tested by Standard 113 aims to achieve. Additionally, standards related to air cleaner testing or duct construction may provide complementary information for a holistic approach to HVAC system design and validation.