Retro-commissioning Protocol for Rooftop Heating, Ventilation and Air Conditioning Units

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Measurement and Verification for Retro-Commissioning of Rooftop Units

Abstract
Building on the work of Retro-Commissioning Pilot Projects in 2008 and 2009, Bonneville Power Administration funded development of methods for measuring and verifying the electricity savings that result from retro-commissioning. Methods will be validated through extended metering of electricity use and deeper analysis of key building characteristics. We also detail data collection requirements. Analysis will support refinement of field measurement protocol, with guidance from the Regional Technical Forum.

Project Team
BPA: Jack Callahan and Mira Vowles
Cadmus: David Korn, Joshua Rushton and Kathryn Hile
New Buildings Institute: Howard Reichmuth

Timeline
2010 - 2011 (in progress)

Reports

• Regional Technical Forum Rooftop Units Working Group (External site)
• BPA Rooftop Unit Pilot Servicing Program Database (2009-2010)

Retro-Commissioning of Rooftop Units Pilot Projects

Abstract
Many existing commercial buildings are thermally conditioned and ventilated by small, packaged rooftop HVAC units. Optimizing the performance of this equipment has significant potential for improving both efficiency and the quality of indoor air in these buildings. During the summers of 2008 and 2009, Bonneville Power Administration (BPA) and its partners examined the energy savings potential of a select package of optimization services. These services were above and beyond normal, preventative maintenance. More than 60 rooftop units were retro-commissioned at 25 sites near Spokane, Washington. In the Puget Sound and Tri-Cities areas in Washington, 200 rooftop units were retro-commissioned at 44 sites.

Efficiency improvements associated with fan cooling averaged 200 kWh per ton annually. But, these savings were not reliable enough to determine a cost-effective regional incentive program. We are optimistic, however, about the energy saving potential of this service protocol. A challenge is observed to balance the required effort of service technicians with the appropriate, cost-effective outcomes. A successful regional incentive program will also motivate building owners to request this service and adequately compensate service contractors performing this valuable work.

Project Team
BPA: Erik Boyer, Jack Callahan, Mira Vowles
Northwest Energy Efficiency Council
PECI

Timeline
2008 - 2009 (in progress)

Reports

• BPA Puget Sound RTU Puget Sound Pilot (2009)