Standard for Direct Geoexchange Heat Pumps

ARI Standard 870: Standard for Direct Geoexchange Heat Pumps

For engineers and designers navigating the complexities of renewable energy integration, understanding the performance and rating of direct geoexchange heat pumps is paramount. ARI Standard 870 provides the definitive framework, offering a comprehensive and authoritative guide to ensure these systems meet rigorous industry expectations for efficiency and reliability.

What is ARI Standard 870?

ARI Standard 870, developed by the Air-Conditioning and Refrigeration Institute (ARI), establishes the essential criteria for the testing, rating, and performance of direct geoexchange heat pumps. Its primary purpose is to provide a consistent and verifiable method for manufacturers to present the capabilities of their products, enabling engineers to select and specify equipment with confidence. This industry-leading standard ensures a common understanding of performance metrics like capacity and energy efficiency.

Scope & Purpose

This standard governs the testing and rating of electrically-driven, mechanical compression type, factory-made residential, commercial, and industrial direct geoexchange heat pumps. It specifically addresses the performance of complete, matched systems, defining parameters for cooling and heating capacities, as well as energy efficiency ratios (EER) and coefficients of performance (COP). Notably, it excludes the rating and testing of retrofit units and individual component assemblies for separate use.

Who Must Comply?

• • Primary audience: Mechanical Engineers, HVAC Designers, Test Engineers, Product Developers, and Building Inspectors involved with geoexchange systems.
• • Industries affected: HVAC Manufacturing, Building Construction, Renewable Energy Installation, and Product Certification bodies.
• • Compliance nature: Voluntary, but often a prerequisite for participation in ARI's certification programs and for product marketing.
• • Enforcement: Compliance is typically verified through independent third-party testing as part of certification programs, with manufacturers self-certifying their adherence to the published ratings.

Key Requirements Overview

ARI Standard 870 outlines several core requirements for direct geoexchange heat pumps:

• • The standard mandates defined rating conditions for both cooling and heating modes to ensure comparable performance data.
• • Professionals must ensure that published ratings for cooling capacity, EER, heating capacity, and COP accurately reflect the equipment's performance under these specified conditions.
• • Key provisions include clear definitions of terminology related to geoexchange heat pumps and their performance metrics.
• • The standard requires specific marking and nameplate data on the equipment to clearly communicate its rated performance and operational characteristics.
• • Manufacturers must adhere to defined test methods for evaluating capacity and efficiency, as detailed in normative appendices.

Related Standards & References

ARI Standard 870 often works in conjunction with other engineering standards. ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration provides foundational definitions. For broader international context and alternative water-source heat pump applications, ISO 13256-1 may be referenced, though Standard 870 focuses specifically on direct geoexchange systems. These complementary standards ensure a robust and interconnected approach to HVAC system design and performance verification.