Typical commercial heating, ventilation, and air conditioning (HVAC) systems present an opportunity for building operators to gain efficiencies and lower costs. Toward this goal, there is an emerging family of products that convert constant-speed rooftop units (RTUs) to variable-speed operation and enable a mix of energy-saving control strategies. These products have been shown in the field to save 25 to 50 percent total heating, ventilation, and air conditioning (HVAC) energy consumption associated with single zone RTUs of 5 tons or greater. The devices provide savings in a wide range of climates, and work best on RTUs that are less than ten years old and still in good running condition. Simple payback periods are typically in the range of one to five years without incentives. This article reviews this technology and provides recommendations for cooperatives considering it as part of business customer incentive or informational programs.

Value to Electric Cooperatives

RTU Variable-Frequency Drives (VFDs) offer another tool for cooperatives to help their commercial members use energy wisely and save energy. Cooperatives should consider evaluating the technology for possible inclusion in business customer programs, as part of cooperatives’ beneficial electrification initiative.


Engineering, Operations, Member Services, Business Accounts, Key Accounts