ANSI/RESNET/ICC/ACCA 310-2025: HVAC Installation Grading
System design, duct integrity, airflow, and refrigerant charge all play a role in residential HVAC performance. When these components are improperly designed or installed, homeowners may face higher energy bills, uneven temperatures, and reduced comfort. According to the U.S. Department of Energy, more than 65% of residential HVAC systems have been estimated to be improperly installed, potentially causing equipment to consume 20% to 30% more energy than necessary. ANSI/RESNET/ICC/ACCA 310-2025, Standard for Grading the Installation of HVAC Systems establishes a consistent methodology for evaluating residential HVAC system design and installation quality through standardized testing, grading criteria, and documentation practices
What Is ANSI/RESNET/ICC/ACCA 310-2025?
ANSI/RESNET/ICC/ACCA 310-2025 provides a consistent, technically rigorous framework for evaluating and grading the design and installation of residential HVAC systems. It establishes the procedures, tolerances, and record keeping practices for evaluating and grading elements of an HVAC system’s design and installation. This American National Standard is intended to support consistency in energy rating and labeling; it is intended for use by home energy raters, energy auditors or HVAC contractors.
What Is HVAC Installation Grading?
HVAC installation grading is a standardized 5-step evaluation process governed by ANSI/RESNET/ICC/ACCA 310-2025 to assess the design, installation quality, and performance of residential heating, ventilation, and air conditioning system.
HVAC Tasks in ANSI/RESNET/ICC/ACCA 310-2025
ANSI/RESNET/ICC/ACCA 310-2025 evaluates residential HVAC installation quality through five sequential steps:
- Task 1: Design review and verification of design tolerances
- Task 2: Total duct leakage testing
- Task 3: Blower fan volumetric airflow testing
- Task 4: Blower fan watt draw testing
- Task 5: Noninvasive refrigerant charge evaluation
The five tasks are designed to be completed in sequence. With the completion of each task, the results are evaluated for compliance with specified thresholds.
Why HVAC Installation Quality Matters for Energy Efficiency
An energy-efficient heating and cooling system can only perform as intended when it is properly designed, installed, and tested. Even high-efficiency equipment may consume more energy than expected if airflow is restricted, ductwork leaks, or refrigerant levels are incorrect. Improper HVAC system design and installation can result in efficiency losses of up to 30%; approximately 20% to 30% of the air moving through a typical home’s duct system may be lost through leaks, holes, and poorly connected ducts.
ANSI/RESNET/ICC/ACCA 310-2025 addresses these HVAC challenges by establishing standardized testing procedures, grading criteria, and documentation requirements to help professionals evaluate residential HVAC installation quality and identify issues that may affect energy efficiency, system performance, and indoor comfort.
Where to Find ANSI/RESNET/ICC/ACCA 310-2025?
ANSI/RESNET/ICC/ACCA 310-2025, Standard for Grading the Installation of HVAC Systems is available on the ANSI Webstore.
ANSI/RESNET/ICC/ACCA 310-2025 was developed by the International Code Council (ICC).
Please direct any technical questions relating to this American National Standard to the developer. You can find the contact information for all ANSI-accredited standards developers here: List of ANSI-Accredited Standards Developers (ASDs).
For further information, please refer to: Who to Contact for Standards Related Questions.
