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New Federal Study Quantifies Efficiency Losses Due To Improper HVAC Installation​

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ACCA, the nation’s largest association of indoor environmental systems professionals, announces the availability of a new report, which confirms that HVAC equipment requires a quality installation (QI) in order to perform at rated efficiency. The research, undertaken by the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST), found that substantial equipment efficiency is lost due to design and installation deficiencies. The NIST report presents faulty practices commonly-performed by contractors and details the resultant additional energy consumption.

The recently-published report is the culmination of a three-year study that included the impact of building effects, equipment effects, and climate effects on HVAC equipment efficiency. The study found that installation faults significantly increase annual energy consumption. Extensive laboratory testing and computer simulations indicated that the following installation faults have the most potential to significantly degrade equipment efficiency: duct leakage, refrigerant undercharge/overcharge, low indoor airflow, and oversized equipment with undersized ductwork. Furthermore, the report shows that when two or more simultaneous faults occur, the efficiency degradations can be additive, compounding the increased consumption.

“This report quantifies what many industry experts already know – profound efficiency losses occur when HVAC equipment is not installed properly,” says Paul Stalknecht, ACCA president and CEO. “This report should help consumers understand why it is important to hire a contractor who follows the QI Standard. When consumers start asking for QI from every contractor, it will raise the performance bar in the industry, and result in significant energy savings while increasing occupant comfort.”

Quality installation (QI) is more than just using high-efficiency products and systems. The correct design, proper installation, and field measurements directly influence the customer’s comfort and how much is paid on utility bills. The ANSI/ACCA 5 QI Standard (HVAC Quality Installation Specification; specifies what to measure, how to measure, and the measurement tolerances for unitary residential and commercial HVAC systems. This reduces faults associated with design, installation, and commissioning. Failure to meet the design and installation elements specified in the ACCA 5 QI Standard will impact equipment performance and undercut the deemed energy savings assumed by many energy efficiency programs.

A full copy of the NIST report, entitled Sensitivity Analysis of Installation Faults on Heat Pump Performance (September 2014), can be downloaded at no charge from

Posted In: ACCA Now, Building Performance, Partner News, Residential Buildings

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