What is the Smart Tools for Efficient HVAC Performance Campaign?

The Smart Tools for Efficient HVAC Performance (STEP) Campaign is sponsored by the U.S. Department of Energy (DOE) and managed by Pacific Northwest National Laboratory (PNNL) to encourage and support the use of smart diagnostic tools that allow residential HVAC technicians to quickly and easily install and commission new HVAC systems and identify and troubleshoot energy-wasting faults in existing systems. The STEP Campaign serves as a national platform for sharing information and recognizing successes of key stakeholders, including HVAC contractors and installers, utilities, energy-efficiency programs, trainers, and others.

STEP Campaign Goals

  • Encourage and support using smart diagnostic tools as a component of quality HVAC system installation or maintenance
  • Provide resources and technical assistance on smart diagnostic tools
  • Encourage use of other connected commissioning technology (i.e., embedded AFDD, third-party leave-in AFDD, etc.)
  • Recognize organizations for adopting or supporting adoption of smart diagnostic tools
  • Document and share best practices and lessons learned 


Space heating and cooling systems account for 44 percent of energy consumption in U.S. residences.1 Improper installation and maintenance of residential heating, ventilation, and air-conditioning (HVAC) systems leads to increased energy use, occupant comfort issues, unnecessary repairs, and decreased system reliability. Researchers estimate that central air conditioners (CACs) and air-source heat pumps (ASHPs) in the U.S. waste 20.7 terawatt hours of energy per year (over a no-fault baseline) due to airflow and refrigerant charge faults alone—that’s 9 percent of national CAC/ASHP energy consumption, costing utility bill payers an estimated $2.5 billion every year2. A recent analysis by DOE’s Office of Energy Efficiency and Renewable Energy (EERE) found that 70–90% of home heating and cooling systems have at least one energy wasting fault.3  

Common faults include improper refrigerant charge, improper airflow, oversized equipment, and duct leakage from improper installation and maintenance practices. Smart diagnostic tools help identify and troubleshoot these potential faults during installation and maintenance. To provide the reliable, high-quality comfort that occupants expect, these units must be installed correctly from the start.

Automated fault detection and diagnostics (AFDD) identify operational issues in HVAC equipment and the underlying causes. In premium variable-speed residential CAC/ASHPs, AFDD is available for monitoring reliability, but does not currently measure energy performance. There are ongoing efforts to develop AFDD for monitoring energy efficiency but these would initially be available only in higher-priced systems. Add-on products (e.g., smart thermostats or professionally installed sensors with cloud-based fault detection) are commercially available but have limited performance monitoring capabilities. Although they may be the future of quality residential HVAC, embedded and add-on AFDD products can only ensure the energy-efficient performance of one system.  

Conversely, a single set of smart diagnostic tools in the hands of a trained HVAC technician can enable quality installation and maintenance, and energy-efficient performance, across many new and existing systems.    

Quality HVAC Systems - The Full Picture

Typical Air Conditioner or Heat Pump Installation

Refer to ACCA Quality Standards for guidance on installation, maintenance, and other aspects of quality HVAC installation. DOE’s Building America Solution Center also provides guidance on quality HVAC system installation:

What are Smart Diagnostic Tools?

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Intro to Smart Diagnostic Tools for HVAC

Smart diagnostic tools are used by HVAC technicians to identify faults in residential HVAC systems by pairing a suite of digital gauges or probes with an HVAC diagnostic application on a smartphone or tablet. The technician temporarily places the digital probes or gauges to measure temperature, pressure, and airflow, and transmit that data in real time from equipment in the field to a mobile application that quickly performs the calculations necessary to verify proper installation, such as superheat, subcooling, and operating capacity and efficiency. To realize energy savings, important features of smart HVAC diagnostic apps include the ability to use real-time data to calculate system performance and capacity, diagnose system faults, and recommend corrective actions. Currently, three diagnostic applications include all these features: Fieldpiece Joblink, iManifold, and measureQuick. 

How Can Smart Diagnostic Tools Help My Organization?

HVAC Contractor

Smart diagnostic tools enable technicians and installers to quickly install or maintain, and properly commission, retro-commission, and perform diagnostics on residential HVAC systems. Contractors that have adopted these tools claim that they increase productivity and reduce callbacks, leading to improved customer satisfaction. Want to learn more? Contact the campaign team or read the STEP Campaign Contractor Case Study

Weatherization Agency

Smart diagnostic tools enable your organization to expand its HVAC quality control capabilities with non-invasive testing. Want to learn more? Contact the campaign team. 

Utility or Energy Efficiency Program Implementer

Smart diagnostic tools have been used in verified quality installation and tune-up programs across the country. These tools streamline the process and add to the transparency of reporting for verified QI/QM programs and equips technicians with the tools and knowledge necessary to provide quality service to homeowners. Want to learn more? Contact the campaign team or check out our Utility and Program Implementer Resources.


  1. Energy Information Administration. 2020. Residential Energy Consumption Survey, 2015.
  2. Winkler et al. 2020. Impact of installation faults in air conditioners and heat pumps in single-family homes on U.S. energy usage. Applied Energy, Volume 278.
  3. EERE, 2019. Residential HVAC Installation Practices: A Review of Research Findings