The 13,400 square foot (1,240 square meter) Landmark building in Yakima, Washington, one of 28 participating Energy Edge buildings.
In the Pacific Northwest, 28 commercial buildings have been built to demonstrate cost-effective energy savings with no loss of occupant amenity. Sponsored by the Bonneville Power Administration, the Energy Edge buildings were designed to use 30% less energy than a baseline building built to the Model Conservation Standards, the regional energy code.
The 28 buildings are typical of new commercial construction in the region: office buildings, schools, fast-food establishments, medical clinics, a supermarket, and a convenience store. Floor areas range from 2,000 to more than 1,000,000 square feet (~200 to 10,000 square meters).
A team from LBL's Energy Analysis Program has been assessing the actual energy use in the buildings and comparing it with that of other new buildings in the region as well as with results from computer simulation models. They now have as much as six years of measured energy use for all but one of the buildings and have analyzed "tuned" simulation results (calibrated with monitored data) for 17 of the buildings. The 28 Energy Edge buildings as a group are using more energy than predicted, but they are, for the most part, low-energy users when compared to other new construction in the region. Based on the results from the first five tuned models, the measures are saving 13% less energy than predicted. Lighting measures as a group are saving more than predicted, but heating, ventilation, and air-conditioning and envelope measures are saving less. Based on two years of utility bills, the average energy use for 12 offices is about 13 kWh/square foot-yr (140 kwh/square meters-yr), slightly higher than predicted, but well below regional benchmark data. Energy consumption for all 28 buildings, based on the third year of utility bills, is increasing in 60% of the buildings.
Energy Edge buildings were designed to use 30% less energy than a baseline building built to the Model Conservation Standards.
Some of the increase in energy use beyond predictions is attributed to poor commissioning and operations and maintenance (O&M) practices. An example is the building where an increase in heating energy outpaced savings from economizer cooling. The culprit: a damper stuck in the open position. On the energy success side, a pilot commissioning project showed that implementing the time-clock functions of the energy management and control system that regulates the lights reduced annual energy use by about 8%. Occupants can also diminish measure performance, sometimes deliberately—as researcher Mary Ann Piette found. In one building, salespeople were required to be in their sales areas on a fixed schedule, "... occupants rigged fans with paper streamers near their motion sensors to keep the lights on! The fans were controlled with a timeclock set to their work schedules."
The Energy Edge evaluation, which has already provided a wealth of information on the performance of energy-efficiency measures in new commercial buildings, will be completed this year. Bonneville is using project results to provide guidance for commercial program design, to upgrade commercial codes, and to revise conservation supply curves. The data also help identify problems with individual measures to improve future applications and to better define commissioning, control, and O & M procedures to optimize energy savings.
—Karen H. Olson
Building Energy Analysis Group
Mary Ann Piette
(510) 486-6286; (510) 486-6996 fax
(510) 486-4740; (510) 486-6996 fax
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