U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Program – Commercial Building Energy Alliances

High Performance Rooftop Unit Challenge

Key Resources

In January 2011, the U.S. Department of Energy (DOE) joined industry partners in the Commercial Building Energy Alliance (CBEA) to release a design specification for 10-ton capacity commercial air conditioners, also known as rooftop units (RTUs). The specification was issued as an "RTU Challenge," since it aimed to catalyze the market introduction of cost-effective, energy-saving RTUs that would significantly outperform any models that were currently available. The CBEA includes an array of building owners that purchase large volumes of RTUs, so their issuance of a specification outlining common performance requirements and desired features represents a powerful demand signal to manufacturers.

Enormous Energy and Cost Savings Potential

RTUs are used in nearly half of all cooling conditioned commercial floor space in the United States. RTUs built according to the specification are expected to reduce energy use by as much as 50% compared to the current ASHRAE 90.1 standard, depending on location and facility type. Nationwide, if all 10-20 ton commercial units were replaced with units built to this specification, businesses would save about $1 billion each year in energy costs. DOE developed an RTU Comparison Calculator so one can easily compare the energy and financial benefits of high-efficiency units to standard equipment.

Primary features of the specification include:

  • High-performance Integrated Energy Efficiency Rating (IEER) of 18
  • Direct digital controls
  • Operational fault detection

Role and Opportunity for CBEA Participants

The RTU Challenge aims to benefit all stakeholders that utilize 10-ton RTUs, so resources like the specification and RTU Comparison Calculator are freely available and promoted via webinars and other public engagement events. As partners in this initiative, participating CBEA members have the added benefit of:

  • Informing the development of the specification
  • Vetting test procedures that are used to evaluate candidate RTUs
  • Leveraging DOE technical assistance to conduct demonstrations of successful RTUs
  • Participating in unique public relations opportunities, such as the CBEA Efficiency Forum, which highlight successes that can be replicated by the broader commercial sector.

As a signal of their support for the RTU Challenge, participating CBEA members issued the following statement:
"We will strongly consider purchasing units that meet the specification, are consistent with our cost-effectiveness criteria, and align with our procurement timeframes. We look forward to working with the manufacturers and DOE to factory witness tests of prototype units that meet this specification. We understand that DOE has committed resources and technical assistance to help U.S. manufacturers design and develop products to meet this specification. We look forward to the near-term market introduction of reliable, energy-efficient and competitively priced rooftop units which increase the energy efficiency of the sector."

Participating CBEA members include:

  • Cleveland Clinic
  • Costco Wholesale Corp.
  • Edens & Avant
  • Grubb & Ellis Co.
  • Gundersen Lutheran Health System
  • InterContinental Hotels Group
  • Lowe's Companies, Inc.
  • Macy's, Inc.
  • McDonald's Corp.
  • Publix Super Markets
  • Target Corp.
  • The Home Depot, Inc.
  • Walmart Stores, Inc.
  • Yum! Brands

Consider joining the CBEA if you are interested in this and similar energy saving projects!

Role and Opportunity for RTU Manufacturers

Participating manufacturers have a unique opportunity to interface with an array of potential customers and DOE technical experts throughout the RTU Challenge. Public relations activities will be pursued at various stages to ensure that news about the RTU Challenge reaches a broad audience, including recognizing successful RTUs and demonstrating such units at CBEA facilities. Each participating manufacturer can only have one product tested by DOE, and there is only one opportunity to pass the test. A candidate RTU will be recognized by DOE as having fulfilled the RTU Challenge if it passes this test.

In order to participate in the RTU Challenge, manufacturers must offer a product that integrates all necessary components, controls, and features needed to satisfy the entirety of the specification (e.g. not manufacturers of individual components). If so, manufacturers can submit an email to cbea@ee.doe.gov indicating their interest, which will initiate discussions with DOE to determine that each of the following RTU Challenge milestones can be met:

  • By May 15, 2012: Share sufficient data with DOE experts to allow for a reasonable assessment that the candidate RTU would pass a thorough, independent laboratory test
  • On May 24, 2012: Participate in the CBEA Efficiency Forum (optional)
  • By August 1, 2012: Facilitate the development of a test plan for the candidate RTU
  • By March 1, 2013: Provide DOE with an RTU for laboratory evaluation according to the test plan
  • By April 1, 2013: Complete all required testing
  • By May 1, 2013: RTU Challenge product available for a field demonstration in a CBEA facility (optional).