Operational efficiency: doing the same, with less

Published on: 
28 Sep 2015
Author: 
Carol Rosenfeld

To many people, “energy efficiency” means swapping out incandescent light bulbs for more efficient LEDs or upgrading an HVAC system. But small operational changes in how a facility or campus operates can result in huge savings as well, without the price tag of retrofits. In fact, FirstFuel has found that low- or no-cost efficiency measures represent over 50 percent of the potential energy efficiency savings in commercial buildings. Operational inefficiencies are often hiding in plain sight, and saving money can be simple if you know where to look. There are four basic things to look at that can help improve your operational efficiency: temperature setpoints, setback scheduling, concurrent heating and cooling and equipment sequencing.

Temperature setpoints

Many institutions (such as Indiana University) choose setpoints of 70 degrees in the winter and 76 degrees in the summer. This is a good first step, but many make the mistake of assigning these same setpoints to the shoulder seasons of fall and spring. For more operational efficiency, analyze the average temperatures in your area. A good rule of thumb is that if the average outdoor temperature is 65 degrees or lower, indoor heating is needed and therefore your setpoint should be at 70 degrees. If the average outdoor temperature is 65 degrees or higher, cooling is needed and the setpoint should be 76 degrees. Identify typical days when the weather in your area switches from requiring heating to requiring cooling and vice versa, and use these dates for setpoint scheduling rather than the equinoxes.  Better yet, if you have an energy management system (EMS) and outdoor temperature data, let the system determine the setpoint based on the weather in real time.

Concurrent heating and cooling

Once you have your setpoints in order, make sure that all the systems in the building are rowing together. The heat should never be on in one part of a building while AC is blowing in another. Submetering can help identify these situations. Alternatively, analysis of real-time data from advanced meters can reveal periods of higher energy use in shoulder seasons (versus the coldest or hottest days of the year), indicating that heating and cooling systems may be working at cross purposes. 

Setback scheduling

Buildings should be set to begin space conditioning when people arrive and stop when they leave. Make sure your buildings aren’t icy cool at 3:00 a.m. in the summer when no one’s there! Beyond that, many schedules assume the building is occupied long before and long after workers arrive and leave. If the majority of people arrive at or after 8:30 a.m. and leave before or at 6:00 p.m., your building temperature setbacks should reflect that. Beginning conditioning at 6:00 a.m. and continuing until 9:00 p.m. doesn’t benefit anybody. FirstFuel found that 60 percent of buildings were cooling/heating an hour or more before people arrived or after they left. 

Equipment sequencing

Finally, if possible, large equipment should be switched on gradually, rather than all at once. When energy-intensive equipment is first turned on, there is a spike in electricity usage. If several pieces are switched on at the same time, the spike can lead to high demand charges, especially if it’s done at on-peak times. This reduces demand charges reduction savings and increases the demand charge opportunity cost. Educate building managers to spread out equipment start-up, or better yet, start equipment on an automated schedule that smooths out flipping the switch.

PEER for Consumer Engagement

Improvements like these have the potential to result in savings of 10 to 20 percent, with minimal costs. Although the control ultimately lies with the building operators, grid operators can support increased adoption of operational efficiency strategies in buildings. For example, projects that provide access to real-time data and consumer engagement programs can earn points toward PEER certification. PEER provides a framework that grid operators can use to engage customers, drive operational efficiency behind the meter and incorporate savings from these strategies into the business case for future grid improvements.