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.
BPA: Erik Boyer, Jack Callahan, Mira Vowles
Northwest Energy Efficiency Council
2008 - 2009 (in progress)