Facility executives in charge of demanding environments—hospitals, pharmaceutical manufacturing and higher education campuses, for example—often are challenged to cut costs and help their organizations meet sustainability goals. Heating, ventilation and air conditioning (HVAC) systems are the natural place to look: these systems typically account for 44 percent of commercial buildings’ energy consumption. Commercial buildings also consume 47 billion gallons of water every day. Optimizing HVAC systems to minimize energy and water use clearly has enormous financial and sustainability benefits.
We have found, though, that HVAC efficiency projects often fail to deliver on their promise. Even new, state-of-the-art HVAC systems lose operational efficiency after installation because system operators take charge, overriding set points and turning to manual control in order to ensure that the HVAC systems meet operational needs.
The HVAC efficiency upgrades that succeed aim for optimization (mechanical systems working at peak effectiveness, all the time) and they follow what we call the three laws of optimization:
1. You cannot optimize what you cannot measure. Without an accurate measure of energy use by each piece of equipment in the system, it is impossible to accurately predict and report the impact of varying conditions on the system.
2. Optimize systems, not just individual components. If an optimization plan focuses only on installing the most efficient pieces of equipment without considering how to maximize performance of the whole system, it won’t capture the total available system efficiency. Holistic automatic optimization of HVAC systems typically increases energy efficiency by an additional 10 to 25 percent over just installing new equipment.
3. Optimization must be automatic, dynamic and continuous for maximum efficiency. Optimization should be a real-time dynamic process, not a static set-and-forget process. If a plant’s operational control is not based on real-time inputs, it cannot be fully optimized.
Facility executives who follow these laws can achieve impressive results, as the following examples illustrate.
- The University of Texas at Austin is saving $1.5 million annually by using the Optimum Energy OptiCx Platform to reduce electricity, steam and water usage.
- The Rockefeller Group reduced emissions at its Time-Life Building in New York (1271 Avenue of the Americas) by nearly 3,000 tons of CO2 annually and received a $557,370 rebate from Con Edison for the OptiCx-enabled energy efficiency improvement. The Optimum Energy system also helped the building achieve LEED-EB certification.
- The University of Maryland Institute for Bioscience and Biotechnology Research used OptiCx to make its environmental stabilization plant, a relatively new facility, 27 to 37 percent more efficient (depending on environmental conditions).
HVAC efficiency is a huge opportunity—with energy use by buildings accounting for one-fifth of the total electricity used in the U.S., there’s too much at stake in terms of resource and carbon savings to ignore it.