EER Optimizer is a patented air conditioner control system with integrated performance optimization and fault detection diagnostics. The EER Optimizer air-conditioner controller continuously monitors performance, and optimizes fan speeds, refrigerant level and flow, and any/all other operating parameters in an operating unit, as cooling load and operating conditions vary, to maximize actual operating energy efficiency. In contrast, the best competing technology can only select a high or low fan speed based on temperature or pressure; and refrigerant level is fixed by the factory initially, and manually adjusted later by a service technician.

Field demonstration under a full range of operating conditions at three sites across a wide range of climates showed that EER Optimizer can bestow a 10% to 30% improvement in system energy efficiency, depending on baseline equipment condition and load and climate factors. Energy savings can reach 50% when needed curative service actions are identified and carried out on units that otherwise appear to be performing satisfactorily.


  • Web monitoring and reporting
  • Optimizes all operating parameters
  • Targets maximum efficiency
  • Continuous performance tuning


EER Optimizer® DX Air-Conditioning Controller

Competitive Advantage

Field testing of three units with the optimizing controller installed resulted in measured cooling efficiency increases of 14.7 to 30.3%, and simulated annual energy savings of 27 to 40%. The results show considerable variability in savings potential depending on the application and climate. Economic indicators were positive for all three applications, giving payback period ranging from 4.5 to 8.1 years and savings-to-investment ratio (SIR) of 1.2 to 2.0. Installation of the technology on the larger 121⁄2 (44 kW) and 20-ton (70 kW) package units produced correspondingly more energy savings, shorter payback period, and higher SIR than the 81⁄4-ton (29 kW) package unit.