Automation, Controls

How smart buildings combat health concerns

Building owners can use sensor technology and centralized building controls to make their buildings safer and more resilient

By Tim King and Ray Mans January 20, 2021
Courtesy: CDM Smith

 

Learning Objectives

  • 1. Learn what a smart building is.
  • 2. Understand some of the approaches to combat a health concern like COVID-19.
  • 3. Explore the strategies used to make buildings smarter.

For decades, buildings have used individual equipment controls and building automation systems to improve heating, ventilation and air conditioning; lighting; and safety and security. Devices and data-driven controls are being integrated into buildings, known as smart buildings, which can monitor, detect and adjust building systems to accommodate the changing demands occurring within a season, a single day or even in real time at any given moment.

Smart buildings — equipped with sensors coupled with artificial intelligence and machine learning — can instantaneously react to changes and then inform building operations teams in real time through mobile devices or desktop applications. Could building owners use these technologies and control capabilities to make their buildings more resilient during a pandemic?

What is a smart building?

What makes a building smart compared to a conventional facility? To understand the role of a smart building, it’s best to look at the evolution of building technology. The drivers behind building technology have traditionally been based on energy use, security and facility operations and maintenance. As smart buildings continue to implement more technology in new ways, we move closer to fully automated facilities tied to a digital twin, the virtual representation of a physical object or system across its life cycle, to perform simulations of building performance and expected occupancy densities and movement and intelligence control of building systems.

Conventional buildings incorporate controls at the equipment level, are not typically controlled or coordinated by a centralized building automation system and are typically confined to control only at the local premise (i.e., piece of equipment). The conventional building relies on scheduled preventive maintenance and building automation to monitor only some systems and is not a fully integrated facility.

Integrated buildings incorporate a centralized BAS that typically controls HVAC, security, lighting and life safety systems. The integrated building can be viewed for diagnostic considerations remotely, which allows the operations team to view real-time facility performance and current equipment issues. This type of facility is the basis for a smart building without the full capability to capture data and alter systems automatically.

Smart buildings use sensors to collect data from each system or equipment and analyze the data using artificial intelligence or machine learning to automatically alter the systems in real time. The “internet of things” application and sensors are comprehensive, provide live data analytics and give the operations team preemptive maintenance information so they can proactively address potential system issues.

The building technology evolution enables facility users and owners to monitor and adjust the workplace — and in some cases, proactively act before any real problems arise. As buildings get smarter, so should owners in fighting unforeseen future pandemics or other health concerns.

Figure 1: Smart buildings are equipped with sensors that provide real-time information for monitoring, controlling and adjusting to any circumstance, such as occupancy, performance, maintenance and building wellness needs. Courtesy: CDM Smith

Figure 1: Smart buildings are equipped with sensors that provide real-time information for monitoring, controlling and adjusting to any circumstance, such as occupancy, performance, maintenance and building wellness needs. Courtesy: CDM Smith

What do we know about buildings and health concerns like COVID-19?

There are several elements to consider when identifying the risk of COVID-19 transmission: distance, time, environment and activity. A strong COVID-19 risk mitigation approach includes an aggressive response to these considerations and requires collaboration with health care, operations, engineers and architects to research, evaluate and implement solutions that consider all perspectives.

COVID-19 and smart buildings

The primary transmission method for a virus is from person-to-person in close contact through respiratory droplets. The closer people are, the higher their risk of transmission is. The Centers for Disease Control and Prevention recommends staying 6 feet apart, reducing sustained contact time to less than 15 minutes and wearing a mask to prevent virus transmission.

However, understanding people movement, patterns and tendencies can be challenging for any building owner. Providing the tools and technology to address these challenges has historically been difficult for owners. Controlling the distance between people and the time spent within closed spaces is key to controlling the spread of viruses.

Most infections occur indoors within workplaces or at large social gatherings. The best way to reduce risk indoors is to provide a healthier environment that addresses the use and activity of the space. For instance, singing and yelling can produce more droplets than normal breathing, which leads to increased risk.

Facilities have several distinct spaces and uses, including transition spaces (walkways) and stationary areas (elevators and restrooms). Each building has a different use and sometimes, they have multiple functions. The workplace environment is a dynamic place where people collaborate, congregate in areas for long periods, pass through spaces for circulation and movement, exercise and perform physical activities.

The dynamic nature of a building means that any response to the spread of a virus or health concern must address the many uses from a space planning and use perspective. Architects and engineers are working with building owners to evaluate options to reduce risk of spread of infectious aerosols. Some of the options under consideration include:

  • Workplace density and space use.
  • Space optimization and strategic communication with building users.
  • Increased ventilation rates and room differential pressurization that can help move air toward exhaust locations, away from occupants.
  • Improved air filtration efficiency rating in central air-handling units or a retrofit high-efficiency particulate air filter box to reduce the airborne load of recirculating infectious particles back into a space.
  • Ultraviolet lights (UV-C) that can damage airborne microorganisms by exposing them to light within the air handlers or ductwork.
  • Ionization of air particles that can have a similar effect as UV light on microorganisms and ultrafine particles in the airstream. Bipolar Ionization is a promising technology that continues to be evaluated.

Strategies to support a healthy building

Understanding the strategies that support a healthy building is a critical step when equipping a smart building to proactively solve facility issues. Before implementing a new technology in a building, designers must first conduct a building readiness plan of the space use and systems. Start by gathering record documents such as as-builts and specifications, recent documentation of HVAC and plumbing systems and commissioning reports. Develop a space use and occupant circulation diagram to best illustrate how people move through the building and how they use each space by identifying pinch points, high-density areas or spaces that need to consider special technology measures. Understand the signage and wayfinding strategies that can be implemented before any new technology is introduced.

Figure 2: “Internet of things” applications and sensors are comprehensive, provide real-time data analytics and give operations teams preemptive maintenance information so they can be proactive about system issues. Courtesy: CDM Smith

Figure 2: “Internet of things” applications and sensors are comprehensive, provide real-time data analytics and give operations teams preemptive maintenance information so they can be proactive about system issues. Courtesy: CDM Smith

These tools are important for building users because they provide them with immediate and clear actions that should be followed, like adhering to circulation paths, sanitizing supplies, maintaining social distancing and gathering only in small groups for short periods of time.

When building users have clear instructions on how to stay safer at the workplace, new technology can be introduced to make the building smarter for the owner to help combat health concerns. Smart buildings can help combat health concerns by using different strategies, including enabling and encouraging social distancing, promoting safe workplace use, improving air quality, reducing the spread of airborne contaminates and providing real-time information to proactively leverage data.

Safe workplaces

Technology can be used to help with social distancing and manage space use by:

  • Monitoring office occupancy density and safe distancing with IoT sensors and analytics.
  • Controlling occupancy in buildings by using video analytics or access control readers.
  • Screening occupants for elevated skin temperature using thermal cameras.
  • Considering how spaces are used (conference rooms, copy areas, lunch/break rooms, cubicles and offices) with data-driven sensors.
  • Providing the owner with contact tracing information from those spaces when an outbreak does occur.
  • Scheduling and staggering occupant strategies to reduce large numbers of people through real-time scheduling, temperature-taking stations, infrared thermometer temperature sensors, isolation rooms or health rooms with increased and isolated HVAC.
  • Adding communication kiosks or screens to common areas to communicate building health and real-time updates on space use and emergency notification of critical events.

IoT technology can get people back into buildings for work or entertainment. Based on current CDC statements, COVID-19 is spread based on exposure time and distance. Smart building technology can help track and reinforce social distancing guidelines. Using real-time data, buildings can get information on dense areas of the building. This information then leads to behavioral changes such as direction arrows pointing people around dense areas or more signage to remind people to keep 6 feet apart. This data could find an unexpected bottleneck and allow buildings to quickly correct the situation.

Most large office buildings require occupants to wear badges while in the building. These badges can easily be used with IoT devices for contract tracing. Using IoT sensors throughout the building, human resources or security departments can trace all of the other badges an infected person came into contact with for an extended period of time. In lieu of isolating or quarantining everyone on an infected person’s floor, only the people traced via badges are contacted about the potential exposure.

Figure 3: The building technology evolution enables facility users and owners to monitor and adjust the workplace — and in some cases, proactively act before any real problems arise. This shows the three types of buildings that are part of this evolution. Courtesy: CDM Smith

Figure 3: The building technology evolution enables facility users and owners to monitor and adjust the workplace — and in some cases, proactively act before any real problems arise. This shows the three types of buildings that are part of this evolution. Courtesy: CDM Smith

IoT sensors can also be used to determine which areas need to be cleaned more or less frequently. With reduced occupancy in office buildings, there are many rooms that are not used daily. In some offices, cleaning crews enter every night to clean the building, even if there are only a few people entering the office each day, working exclusively at their desks, not conference rooms or other communal spaces. The cleaning crew wipes down every surface, including those unused conference rooms, every evening.

IoT devices can accurately identify areas that are not used and can potentially be skipped in the cleaning rotation. The devices can also spot heavily used areas and alert the building operators when cleaning is needed more frequently. In conjunction with badge-tracing, cleaning can quickly be directed to the areas that an infected person accessed. This real-time data maximizes the efficiency of cleaning and provides a safer environment.

Indoor air quality

Since COVID-19, air filtration and treatment have been discussed frequently as mitigation measures. IoT devices can be used in the HVAC system to display the indoor air quality throughout the building —covering much more of the building than wired sensors can. Wireless IoT sensors distributed throughout the spaces, about every 100 square feet or so, can show temperature and/or humidity variations in the space. The IoT sensors show a granular level of performance that a traditional sensor mounted near a door cannot provide. In turn that can alert the building to potential relative humidity issues or, at a minimum, poor air distribution.

The ASHRAE recommends a MERV-13 at a minimum for better filtration of the particles carrying viruses. If MERV-13 filters are retrofit into an existing system, it’s important to track the pressure drop as the filter becomes loaded. With the higher initial pressure drop of MERV-13 filters compared to the typically installed MERV-8, newly installed smart sensors can provide real-time feedback, allowing for optimized filter changes.

In a building that relies on scheduled filter changes or observing pressure gauges manually, new IoT sensors can save maintenance personal time and maintain indoor air quality. Smart sensors are also available to track particulate levels PM1, PM2.5 and PM10 for a higher level of information. The particulate data can be sent to a central kiosk to show employees how well the building is filtering out particulates. After COVID-19 this level of detail is helpful for allergy and asthma suffers. A kiosk could be placed in a central location to inform building occupants of the general health of the building.

Real-time smart building data

Building HVAC plays a significant role in employee health and productivity. As we adapt to the changes resulting from the pandemic, there is a heightened awareness of the buildings that we work in. IoT devices can provide more indoor air quality data across more area for a smaller cost compared to expanding the BAS.

The BAS provides a significant amount of data, from various sources, to a central location. This data typically includes air-handling unit air temperatures, building lighting and building access. All data collected by the BAS must be analyzed. If facility personnel are unavailable to quickly analyze the data, then the analysis will likely be delayed.

IoT devices, using cloud computing and storage, can lessen the analysis burden by providing clear insights directly to facility personnel. This allows facility personnel to proactively make decisions, rather than reactively. As more data from the building and equipment is collected, machine learning or artificial intelligence can notify the building to allow for predictive maintenance.

Cost savings is a key benefit of fixing equipment within the building before it breaks. Predictive maintenance can help facility owners better plan for upgrades and minimize occupant concerns or complaints by maintaining the HVAC systems at their specified operating conditions.

With BAS, the building HVAC is scheduled to operate at a specific time each day. Due to COVID-19, most office buildings are operating at a reduced occupancy rate that will continue for the foreseeable future. With smart sensors and application-based booking, a higher level of HVAC control is possible. Instead of running an HVAC system 7 a.m. to 7 p.m. Monday to Friday, the system can be scheduled based on online booking of the space.

The smart sensors in the space can also communicate with the HVAC system that the space is occupied or unoccupied. Using a smart sensor provides instant space control, compared to using a carbon dioxide sensor where the HVAC system is delayed until the CO2 sensor hits its setpoint.

For example, a conference room could be booked for four hours midday. The HVAC would “see” this reservation and condition the space for those four hours. If the meeting is extended, live sensors would alert the HVAC system that the conference room is still occupied via the IoT sensor and continue to condition the space without any occupant action.

The opposite would also hold if the area is reserved but remains unoccupied. Based on the IoT sensor, the HVAC unit would go into temperature setback mode and then will return to occupied mode once it senses people are in the space. Using online scheduling with a new smart sensor to dynamically setback space temperatures when not in use could provide savings to help offset the higher energy costs associated with other COVID-19 mitigation strategies.


Tim King and Ray Mans
Author Bio: Tim King is an architect and vice president at CDM Smith. He has 27 years of experience in architectural programming, planning, design and construction. Ray Mans is a mechanical engineer at CDM Smith with more than 20 years of experience designing building mechanical systems.