This article explores the energy usage and control decisions that companies are making as they recalibrate their buildings’ HVAC operational requirements.
Due to the COVID-19 pandemic, many U.S. businesses operating from commercial buildings experienced either a shutdown or a substantial reduction in facility usage this past March. These abrupt changes in operations caused immediate and extensive economic consequences that continue today. With the gradual reopening of the economy, companies are faced with the pressing challenge of implementing measures that minimize the spread of the novel coronavirus while lowering their operating cost structures.
Scientists and system engineers have looked at the various ways building systems should operate under epidemic and post-epidemic conditions. To help companies be best prepared, ASHRAE updated its Building Readiness information for commercial buildings in August. The online resource provides practical guidance on operating building systems, addressing important topics such as ventilation, building automation systems (BAS), exhaust, and filtration. Facility managers are being asked to operate buildings in ways that differ widely from original design conditions.
This article focuses on the shifts in energy use and how companies can realign their HVAC control practices to minimize energy consumption and spending.
Before and after shutdowns: A look at energy use
The extraordinary implications of the coronavirus lockdowns led to the biggest global fall in energy demand in 70 years.1 As broad categories of businesses either shut down or sent their team members home to work remotely, commercial building energy usage across the country declined significantly by mid-April, as reported by Greentech media.2 Encycle, a company that leverages IoT technology and machine learning to help commercial entities lower their HVAC energy usage and costs, saw most of its customers dramatically curtail their building operations in mid-March. Figure 1 below illustrates the steep decline in HVAC energy consumption for typical Encycle customers when most facility shutdowns first occurred. As a side note, many analysts view this type of energy usage data as an indicator of how the economy is performing, since most economic activity requires energy.3
Encycle also compared the HVAC energy usage of its customers in August 2019 versus August 2020 (figure 2). The source data was collected in real-time using Encycle’s patented Swarm Logic® cloud-based software. The data show the stark changes these historic events have had on commercial and industrial businesses, as examples of a nationwide story.
Our data shows that customers’ HVAC energy consumption is 7 to 15 percent lower than before COVID entered the picture. This reduction in energy usage is largely driven by reduced hours of building utilization, fewer employees and customers in the buildings, and less equipment operation. These decreases in HVAC energy usage are partially offset by the dramatic increase in the volume of outside air being brought into buildings to help flush out potential airborne contaminants as part of each company’s COVID mitigation strategy.
Changes in occupancy prompt new HVAC energy efficiency considerations
The abrupt changes due to concerns about the COVID-19 pandemic caused massive unemployment and created new work-from-home policies. According to the Bureau of Labor Statistics, the unemployment rate was 11.1 percent in June.4 Also in that month, 42 percent of the U.S. labor force was working from home.5 In recent research conducted by the Society for Human Resources Management (SHRM), about 17 percent of HR leaders in 2,284 U.S. companies reported their organizations will move to permanent work-from-home policies in the future.6
Given the reduced occupancy in office buildings, restaurant chains, retail stores, and other facilities, building owners and managers have adapted their HVAC setpoints and schedules from their standard energy-saving modes to unoccupied or other flexible schedules to minimize energy use and costs in response to the “new normal” for facility utilization. Having this critical capability helped reduce the financial impact of the pandemic on businesses. According to the U.S. Department of Energy and Environment, a commercial building can save up to three percent on energy costs for each degree the thermostat is raised during cooling months.7
As businesses continue to reopen facilities and bring workers back to work under new conditions, it’s imperative that companies gain a better understanding of the way they are using HVAC-related energy and how to maximize HVAC efficiency when building usage does not correspond with original design conditions.
While changing setpoints and schedules in response to a dramatic shift in facility operations may yield some relief, they will not likely yield optimal HVAC energy efficiency. These changes in building operations, along with make-up air efforts, can significantly impact the thermal load profile of a building and the efficiency of its HVAC equipment. Existing HVAC control approaches may fall short, especially when it comes to rooftop unit (RTU) operations. Here’s why:
- The HVAC and building control equipment was designed and configured to optimize energy efficiency for a pre-COVID “normal” building operational profile. Traditional approaches to adapt the operating design to the “new normal” would require significant manual effort to reconfigure equipment to optimize energy efficiency for a post-COVID profile.
- The building controls typically cannot identify and proactively respond to fluctuations in outside temperatures or building occupancy.
- Occupant comfort may be compromised.
- Traditional HVAC control approaches do not synchronize the operation of multiple RTUs, resulting in deficits in performance efficiency.
Autonomous machine learning-based HVAC control delivers greater flexibility and savings
While 2020 has started as a turbulent decade, smart technologies offer promising new capabilities that operate automatically to ensure HVAC equipment is running as efficiently as possible. The latest building trends rely on data gathering and machine learning to deliver energy-saving results like never before, while reducing the burden for facility managers who may struggle to optimize HVAC efficiency through business close/reopen/close scenarios. Only by deploying machine learning technologies like Swarm Logic can a facility manager optimize HVAC energy usage amidst dramatic shifts in energy usage demands and patterns. Companies that embrace more adaptable systems and control technologies will be better able to manage their HVAC-related energy consumption and savings.
Contributing author: Chris Hensley, Executive Vice President of Sales and Marketing, Encycle Corporation
1 Written by Douglas Broom, Senior Writer. “5 Things to Know about How Coronavirus Has Hit Global Energy.” World Economic Forum, World Economic Forum, 18 May 2020, www.weforum.org/agenda/2020/05/covid19-energy-use-drop-crisis/.
2 John, Jeff St. “Why Empty Office Buildings Still Consume Lots of Power During a Global Pandemic.” Greentech Media, Greentech Media, 15 Apr. 2020, www.greentechmedia.com/articles/read/how-office-buildings-power-down-during-coronavirus-lockdown.
3 Bui, Quoctrung, and Justin Wolfers. “Another Way to See the Recession: Power Usage Is Way Down.” The New York Times, The New York Times, 8 Apr. 2020, www.nytimes.com/interactive/2020/04/08/upshot/energy-usage-predict-coronavirus-recession.html.
4 “Unemployment Rates up in 388 of 389 Metro Areas in June 2020.” U.S. Bureau of Labor Statistics, U.S. Bureau of Labor Statistics, 3 Aug. 2020, www.bls.gov/opub/ted/2020/mobile/unemployment-rates-up-in-388-of-389-metro-areas-in-june-2020.htm.
5 University, Stanford. “A Snapshot of a New Working-from-Home Economy.” Stanford News, 26 June 2020, news.stanford.edu/2020/06/29/snapshot-new-working-home-economy/.
6 Weiss, Todd R. “More Companies Likely to Keep Employees Working from Home until 2021 Due to COVID-19.” TechRepublic, CBS Interactive, 15 May 2020, www.techrepublic.com/article/more-companies-likely-to-keep-employees-working-from-home-until-2021-due-to-covid-19/.
7 John, Jeff St. “Why Empty Office Buildings Still Consume Lots of Power During a Global Pandemic.” Greentech Media, Greentech Media, 15 Apr. 2020, www.greentechmedia.com/articles/read/how-office-buildings-power-down-during-coronavirus-lockdown.