Over the past 25 years, substantial gains have been achieved in the energy efficiency of residential central air conditioners and heat pumps.
November 28, 2016
minute read time
A technician installs central air conditioning equipment.
The Brief
- The design and installation of a home’s HVAC equipment can have a significant impact on system energy consumption, regardless of how efficient the base equipment is.
- Industry actors have long recognized the importance of proper installation to the performance of residential heating and cooling systems, but adoption of installation best practices by HVAC contractors has been limited.
- The Energy Department recently convened a workshop to capture stakeholder input and recommendations for advancing best practices in residential central air conditioning and heat pump installation.
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Over the past 25 years, substantial gains have been achieved in the energy efficiency of residential central air conditioners and heat pumps. A typical product manufactured today is over 50% more efficient than typical equipment produced 25 years ago, and several products now achieve ENERGY STAR’s Most Efficient designation. Federal energy policies, like minimum equipment standards and tax credits for efficient products, have had a substantial impact on improving the efficiency of residential central air conditioners (CACs) and heat pumps (HPs), producing energy cost savings for consumers.
Just as important to delivering energy savings as better equipment itself is the proper installation of CAC and HP equipment. For example, a 2014 Technical Note by the National Institute of Standards and Technology (NIST) estimated that improper installation practices—including incorrect refrigerant charge, oversized equipment, low airflow, and undersized and leaky ductwork—could increase HP energy use by up to 30%. Several field studies in recent years have indicated that these faults are not uncommon, yet CAC and HP system design and installation are often overlooked.
Recognizing the significant impact of system installation faults on energy and utility bill savings, several organizations have participated over the past 25 years in the development of industry-recommended best practices for the design and installation of systems and equipment. One example is an ANSI quality installation (QI) standard for heating, ventilation, and air-conditioning (HVAC) equipment, released by Air Conditioning Contractors of America (ACCA) in 2007 and updated in 2010. Unfortunately, though best practices for system installation are widely recognized in the industry, adoption by HVAC contractors has been limited.
This past May, the Energy Department’s Building Technologies Office (BTO) hosted a one-day workshop with experts to discuss strategies for increasing the adoption of system installation best practices for residential CAC/HPs. During this workshop, stakeholders emphasized the need for research, development, and deployment (RD&D) investments to better understand current CAC/HP installation practices, encourage wider awareness and adoption of QI practices, and develop next-generation technologies and policies. A new BTO report, Residential Central Air Conditioning and Heat Pump Installation–Workshop Outcomes, captures these and other recommendations, providing valuable stakeholder input that can help BTO establish future priorities to advance HVAC system efficiency through its RD&D portfolio.
Currently, BTO has several planned activities that address some of the recommendations in the report. Furthermore, state and utility program managers can rely on existing DOE resources to encourage the adoption of QI best practices when offering incentives for high-efficiency equipment.
Weatherization Assistance Program
DOE’s Weatherization Assistance Program, which provides grants to states, territories, and Indian tribes to improve the energy efficiency of the homes of low-income families, has introduced a comprehensive Quality Work Plan. This Plan seeks to ensure all measures and incidental repairs performed on client homes meet the specifications, objectives, and desired outcomes outlined in the Standard Work Specifications for Home Energy Upgrades (SWS). Many of the HVAC QI best practices, recognized in ACCA’s QI standard, are included in the SWS.
Building America
DOE’s Building America Solution Center is a valuable source of technical information, with new content constantly being added. A quick search of current resources returns several technical guides related to HVAC installation, including:
- How to air seal seams and holes in HVAC air handler and furnace cabinets
- How to air seal ducts and flue shafts
- How to conduct duct leakage tests on all components of the HVAC system
Several years ago, an innovation sponsored by the Building America program led to the development of injected spray sealant for existing HVAC ducts. This approach was commercialized in 2001 and is available in the marketplace today as Aeroseal®. Today, Building America continues to accelerate energy performance improvement in residential buildings, and the program recently released a funding opportunity announcement (FOA) for additional building science project teams. The submission deadline for concept papers is December 7, 2016. More information on this FOA can be found at /eere/funding/eere-funding-opportunities.
Home Improvement Catalyst
The Energy Department’s Home Improvement Catalyst (HI-CAT) is working with Midwest Energy Efficiency Alliance to document best practices from successful QI programs in the Midwest, and is helping Northeast Energy Efficiency Partnerships (NEEP) to develop technical guidance and outreach resources to encourage adoption of cold climate heat pump technologies in the Northeast. HI-CAT will also be working to identify benefits and best practices for adopting of advanced HVAC installation and diagnostic solutions to optimize system performance efficiency and comfort, in conjunction with EPA’s ENERGY STAR Verified HVAC Installation (ESVI) program, which addresses many of the installation faults identified in the NIST research.
Working together, industry, efficiency program partners, and the Energy Department can increase the adoption of QI best practices, leading to improved comfort and energy cost savings for consumers.