Addendum to ARI Standard 880-98, Air Terminals

ARI Standard 880-98: Addendum to ARI Standard 880-98, Air Terminals

For HVAC engineers and product designers, understanding the performance and certification of air terminals is essential. The ARI Standard 880-98, and its crucial addendum, provide industry-leading guidelines for specifying, testing, and rating these critical components of building ventilation systems. This addendum, specifically, addresses a significant advancement in air terminal technology, ensuring that the standard remains relevant and comprehensive for modern HVAC design.

What is ARI Standard 880-98?

ARI Standard 880-98, originally established by the Air-Conditioning and Refrigeration Institute (ARI), sets forth definitions, classifications, testing procedures, and rating requirements for air terminals used in commercial air distribution systems. Its primary purpose is to ensure consistent and reliable performance data for these devices, facilitating informed specification and design by engineers and manufacturers.

Scope & Purpose

This standard governs the testing and rating of air terminals designed to modulate air volume and/or temperature in response to varying building loads. It specifically applies to ducted air control and distribution devices, including those with directional vanes, pressure-dependent or compensated dampers, heat exchange capabilities, and fan control mechanisms. However, it explicitly excludes basic registers, diffusers, grilles, and retrofit units, focusing instead on more complex terminal devices that actively regulate airflow and temperature.

Who Must Comply?

• • Primary audience: HVAC engineers, product designers, test technicians, certification managers, and building systems specifiers.
• • Industries affected: HVAC manufacturing, building construction, mechanical engineering, and product certification bodies.
• • Compliance nature: Voluntary conformance is encouraged for manufacturers seeking to participate in ARI's certification program, which provides verified performance ratings.
• • Enforcement: Compliance is typically verified through participation in the ARI certification program. While not always mandatory for all market segments, certified products provide assurance to specifiers and building owners.

Key Requirements Overview

The addendum to ARI Standard 880-98 introduces specific provisions for modulating diffuser units, a type of air terminal not originally detailed in the 1998 version. Key requirements and updates introduced by this addendum, and the parent standard, include:

• • The standard mandates clear definitions and symbols for air terminal types and their performance characteristics.
• • Professionals must ensure that testing procedures accurately reflect real-world operating conditions for air terminals.
• • Key provisions include requirements for rating essential performance metrics such as primary and induced airflow, electrical power input, operating pressure, and sound power levels (both discharge and radiated).
• • The standard outlines minimum data requirements for published ratings, ensuring transparency and comparability among manufacturers.
• • Specific additions in the addendum detail how to incorporate and test modulating diffuser units within the established framework of ARI Standard 880-98.

Related Standards & References

ARI Standard 880-98, and its addendum, are often used in conjunction with other industry standards. ARI Standard 885, for instance, provides a complementary procedure for using the sound ratings generated by Standard 880 in estimating sound levels within occupied spaces. Furthermore, standards from ASHRAE provide foundational definitions and terminology that are referenced within ARI 880-98, ensuring