In one western Oregon location, four packaged rooftop HVAC systems were retrofitted with the goal of improving efficiency of electricity use for ventilation. Improvements include a western premium economizer upgrade, optimum start thermostat, variable speed fan motor, and demand controlled ventilation (DCV). Our research sought to develop standards for cost-effective retrofitting and tools for predicting efficiency following the upgrade. Phase 3 will result in an evaluation of potential for a regional pilot program.
While our study demonstrated significant savings, we identified and addressed several shortcomings. The retrofit protocols were updated to more appropriately match motors and single-phase, variable-speed drives. Acceptance testing was improved based on the complexity of sensors needed for DCV. Programmable, direct digital control thermostats should be tested before pilot program deployment. This should alleviate the difficulties in setting analog or solid state economizer controllers; more reliability and ease of installation could result from a different approach.
BPA: Mira Vowles
PECI: Reid Hart
Eugene Water and Electric Board
City of Eugene
Energy Trust of Oregon
2008 – 2011 (in progress)