Sandbox

Objective

This section explores how the next generation of smart building operations, functionality and maintenance is utilizing the (IoT) internet of things to operate at full interconnectivity, functionality and efficiency. Smart building, operations, functionality and maintenance capabilities cut energy consumption and CO2 emissions, reduce maintenance costs and extend equipment lifetime. Various systems offer actionable insights, drive fewer complaints from occupants, decrease the need for unscheduled maintenance and reduce energy costs and carbon footprint. In time of pandemic or other extreme events, smart buildings may offer autonomous operation.

For many people, the idea of a SMART building creates and implies an image of a building with complex IoT applications that can only be understood, integrated and operated by a cadre of a highly trained facility, IT, and project management professionals. A similar apprehension existed with the first generation of buildings with BAS (Building Automation System)— i.e. an intelligent system of both hardware and software, connecting heating, venting and air conditioning system (HVAC), lighting, security, and other systems to communicate on a single platform. Most larger buildings today have a BAS system for significant energy saving and operational benefits it provides.

An introduction of AI systems now expands the operational capabilities and even suggests the possibility of fully autonomously operated buildings, connecting with and responding to the signals from the grid.

Smart Building Operations

The difference between BAS and the smart, connected building operations

The difference between BAS and smart building operations is the ability to gather data, analyze and diagnose problems from multiple data input sources. Building automation systems (BAS) help facility owners conserve energy and optimize performance with controls that allow for examples like scheduling, occupancy and maintaining set-points. Smart building operations are a step ahead from this, and represent a facility's ability to gather the data and change operational outcomes accordingly. The key is data acquisition, analytics, and diagnostics.

The transition to smart operations does not have to occur all at once but can be gradual and phased. For owners with a robust, and at some levels integrated BAS in their facilities today, transitioning to a smart building environment will be easier to accomplish.

The very first step is to install smart meters that can provide near-real-time energy usage data showing energy consumption, and in some cases, at what cost. This on its own has the advantage of improving a building operator's insights to save energy, reducing the carbon footprint, improving the longevity of equipment and reducing costs. Smart meters offer utility monitoring opportunities on a more granular basis toward the conservation of our natural resources. The systematic tracking and optimization of building energy consumption with visual dashboards can also help not only to change the behavior of building occupants but also connect and make the building responsive to the price and demand signals from the grid as connected buildings. Blueprint Chapter 6 – Interfacing with City Services and Utilities provides further explanation.

The building operation KPI’s

How do we evaluate the effectiveness of the building operations? The KPI’s for the building operation are:

• Lower energy performance gap: building operation presents several inefficiencies compared to project conditions that lead to an energy performance gap. This gap can be reduced by monitoring systems.
• Lower maintenance and replacement costs: smart-ready services reduce maintenance and replacement costs since they permit to prevent or detect faults and failures.

Using the holistic H-KPI framework1, provides a more comprehensive view, enables aggregation and normalization of smart building indicators, and allows better quantification and comparison of operations in different types of buildings, The H-KPI;s use three levels: Level 1- technology, Level 2- infrastructure and level 3 – benefits.

The interactions across the three levels of analysis is a central component of the H-KPI methodology. For example, sensors deployed at Level 1 inform the building management infrastructures at Level 2. The benefits of deploying the smart controls are then manifested at level 3.

Figure 1: Operational and Energy Savings

Level 1 Technology

The first step is to install sensors to monitor building performance in real-time. Sensors provide data to a one or more processing units that uses that information to drive heating and cooling equipment as well as actuators, dampers, fans and other components to control a building's operation. They are capable of collecting environmental and operational data of buildings and reacting to the collected information in real time. They are the front end of smart building systems.

From a data standpoint, a commercial building is a complex business with diverse needs. The right combination of sensors in an integrated network is worth much more than the sum of its parts, with significant value for predictive maintenance, operational efficiency, downtime reduction, environment stabilization, and occupant comfort1. The following are the type of sensors found in smart buildings:

Pressure Sensors:

AHUs, chillers, and boilers all need pressure sensors to monitor pressure in ducts, condensers, and evaporators, and water supplies. High or low pressure readings are an invaluable predictor of leaks, pump failures, locked rotors, clogs, and other mechanical failures. They’ll provide proof of flow and can be used as a control point for things like fan speeds or air flow through duct work. You’ll also be able to monitor building zone pressure to regulate the inflow of outside air.

Humidity Sensors:

Many facilities have precise environmental humidity requirements — laboratories, libraries, manufacturing plants, et cetera — due to the materials or processes housed within them. Even in office and residential buildings, however, humidity regulation is a critical component of occupant comfort. Humidity sensors within air handling units help you determine how much outside air you need to introduce into the building and keep you timely in your response when RH is exiting the desired range.

Temperature Sensors:

Few sensors see more widespread use in HVAC than temperature sensors, which play crucial roles in virtually all units. Your temperature sensors will monitor duct temperatures, chilled and heated water loops, inside and outside air temperatures, and more. They also provide input for functions such as fan or valve control and flow regulation.

Current Sensors:

These are essential for tracking the run status of all fan and pump motors. A current sensor provides proof of function and eliminates the need to manually check each unit to see if it’s running. If current is flowing, the unit is working.

CO2 Sensors:

The best way to reduce costs on constant conditioning of outside air is to track CO2 for Demand Control Ventilation (DCV) and either recirculate inside air or introduce fresh air, as needed.

Power Meters:

A power meter in a chiller or boiler helps with the efficient management of load shedding agreements and detection of mechanical problems (when, for example, power usage is excessive).

Flow Meters:

Water flow (both return and supply lines) must be monitored in boilers, chillers, or cooling towers to provide proof of flow and measure usage. BTU meters are a version that combine the functions of flow meters and temperature sensors to trend energy usage and detect inefficiencies (which may result from clogs, excessive ice, humidity changes, and other malfunctions).

Current Switches:

These devices track amperage (current) that passes through a conductor. The format of the switch will vary, depending on the application. They’re useful in monitoring the status and run times of circuits, motors, and equipment while also detecting mechanical failures.

Current Monitoring Relays:

A relay can provide a layer of protection for mechanical equipment that may overload under excessive currents. A load-switching relay can easily handle resistive currents for lighting fixtures (e.g. incandescent, LED, fluorescent), and capacitive currents (such as power supplies and loudspeakers). Inductive loads, as with fans, transformers, and electromotors, require careful attention to maximum loads to prevent damage to the relay.

Current Transducers:

A transducer modifies an electrical input to a different kind of signal either passively or actively. These are used for monitoring load trending data and the controls and status of the equipment (such as a fan or pump) receiving the altered signal.

Indoor Air Quality (IAQ) Room Sensors:

IAQ compliance requires careful monitoring of the indoor climate with sensors that track RH, CO2, temperature, and VOC outputs. It’s also critical to track these things for the general comfort and safety of occupants and to protect sensitive materials or equipment. Such units can be wall or ceiling-mounted, and fitted to be controlled by hand or remotely via the BMS or even a wireless application. While it is possible to install individual sensor types for each aspect of IAQ, the best and most cost-effective approach would be to install a network of all-in-one style sensors with the capability to monitor every aspect (or as many as possible) from a single device in each location.

Occupancy Sensors:

When it comes down to it, building management is about keeping a building functional and cost-efficient for the people and processes housed within. This is most achievable with an accurate data model on space usage — where, how long, and in what numbers people are residing in the building — to guide the setpoints and schedules in your system. Some systems can be turned down or off, even during times the building is in use, if certain areas are less active or perhaps not active at all. Data from occupancy sensors will guide planned maintenance outages, field service of equipment, energy management for peak hours or off hours, and more.

For example, temperature sensors allow you to measure and monitor ambient, or surface conditions in or around the building, in real-time. This allows you to maintain optimum conditions and improve efficiency. Desk occupancy sensors detect and monitor the presence of people, in real-time.

Where (and Why) Should Sensors be used?

Sensors and meters need to be integrated throughout the building, from individual flow meters within the valves of a boiler’s hot water loop to a simple wall thermostat in the lobby. Each sensor acts like a nerve that connects HVAC, power, lighting, and other systems to the BMS for a complete picture of unit health and performance. It’s critical that sensors are installed within the following units and systems for an optimal set of control points and insights.

Air Handling Units (AHU):

The AHU will use an array of pressure, humidity, temperature, current, and CO2 sensors to keep operations efficient and help you optimize setpoint automations and strategic cycle scheduling. Pressure sensors keep track of filter status, whereas RH, CO2, and temperature sensors should be positioned periodically in all ducts. A current sensor monitors each fan motor.

Water Cooled Chillers: The chilled water loop and condenser water loop will need temperature sensors to help you better control the valve that determines circulation speeds. Return and supply lines use flow meters to provide proof of function and gauge pressure sensors to enable the BMS to calculate differential pressure between supply and return. A current sensor is needed for all pump motors to detect on/off status, locked rotors, and functionality.

Cooling Towers:

Use a flow meter on both the supply and the sewer drain to reduce your costs. The meter helps you detect how much water went down the drain by showing the difference between the volume of water initially supplied and the water discharged into the sewer. As much as 50-60% could be lost to evaporation. Proving this will save on utility charges that assume all water supplied was also sent into the sewer system. Immersion temperature sensors are a useful control input for fan rotation, and as with other units, current sensors should track all pumps and fans to ensure they’re working.

Variable Air Volume (VAV) Boxes:

Temperature sensors provide the needed input to control dampers, fan speeds, or power to suit the demands of the space. VAV boxes with heating and cooling coils will also use temperature sensors to control those points. A current sensor monitors the fan motor (and thus the fan status).

Boiler Systems:

The boiler requires a complex network of sensors to track power, pressure, current, temperature, and flow. The power meter assists in regulating load shedding processes as well as detecting issues in the boiler pump motor. Current sensors also provide proof of function for the pump motor. Gauge pressure sensors monitor the supply and return lines for total pressure (and allow for calculation of differential pressure). Temperature sensors track the heated water loop to help you determine pump speed and control the valve for water recirculation with efficiency. BTU flow meters are a valuable input for trending boiler efficiency and measuring the total energy it consumes. Overconsumption can indicate compressor cycling issues, clogs, or malfunctioning pumps.

Current Monitoring System:

An optimal energy bill depends upon efficient management of your energy consumption. Modern power and current monitoring systems must provide more than a whole-building view. Individual breakouts of performance and trends at each circuit enable you to pinpoint energy consumption, detect inefficiencies or problems, and predict electrical or equipment-based maintenance needs. It’s best to meter as many lighting circuits, fans, motors, pumps, and equipment power supplies as is feasible. An ideal meter can accurately monitor 50, 100, or potentially even more circuits — you won’t need a matching number of meters to make individual monitoring possible.

All Occupied/Sensitive Interior Spaces:

Wall-mounted and ceiling-mounted IAQ and occupancy sensors can be easily fitted for every room or hall that will be occupied or contain climate-sensitive materials or equipment. Keep precise track of the humidity, temperature, and CO2/VOC levels in these areas to detect potential blockages or failures in the ventilation system and to respond quickly to increased needs in times of high occupancy. In many applications, these sensors will also be necessary to help you maintain compliance with codes for the space.

IoT connectivity

To support such a massive connectivity required for the deployment of sensors, demands many wireless technologies are investigated. The existing wireless IoT connectivity technologies include diverse types of connectivity technologies, such as LPWAN, 5G, WIFI, IP with different specifications and performance characteristics.

Figure 2: IoT systems overview

Level 2 Infrastructure Services

The current technology, otherwise known as Big Data Analytics (BDA) and Fault Detection and Diagnosis (FDD), typically consists of a cloud-based analytical engine that receives and analyzes building data and communicates the diagnostic information, typically through a series of work orders. These are the terms used to describe the process of tracking and analyzing building performance and energy efficiency continuously and in real-time of heating, ventilation and air conditioning (HVAC) systems, lighting (for example, daylight saving and shutting off lights in unoccupied zones), indoor air quality (IAQ) monitoring, smart elevators and so forth to alert the building operators of faults or inefficiencies within the building systems. To avoid being overwhelmed by too many notifications, algorithms can be put in place to prioritize and indicate the work orders that are a priority, and which will have the greatest positive impact on building performance.

Fault detection and diagnosis enable timely and targeted interventions in cases of faulty or underperforming building equipment. This equates to continuous commissioning. Smart building sensors are not limited only to energy usage problems but can also address other systems, for example, identifying water leaks, or waste bins that need emptying. In the longer term, BAS will soon become less important, as more and more equipment will be manufactured with integrated controls and sensors that can be wirelessly connected to the network and driven by a smart building software platform — like 'plug and play. As more and more data and the skill set to collect them increase, the analytics will mature and reveal patterns and feedback mechanisms that will enable the development of data-driven knowledge and operations. Like self-driving cars, this may lead to self-operating buildings, where the analytic and diagnostic capabilities of smart buildings will allow for remote operation of the buildings. With the information relayed via the cloud about the operation of the building's heating, ventilation, air conditioning (HVAC) and lighting control systems, the building operator will be able to monitor and control the building operations remotely for energy consumption. This is also valuable in times of emergency, such as pandemics.

The difference between remote, cloud-based and on-premises, edge computing infrastructure1

The AI now being deployed started life as a cloud computing technology. The machine learning algorithms under the hood of these systems require significant computing power, both to train the algorithms and get them to deliver insights – a process called inferencing. Until recently, on-premises infrastructure rarely had the resources to effectively do those things and, as such, building operators had to run their AI applications out of data centers.

Yet, running smart building applications out of remote data centers has its own limitations. Connectivity, bandwidth costs, security and latency – the time it takes to send data to the cloud and back – can impact a system’s efficacy. If a machine, or an entire building automation system, is going to fail, the alarm and automated response need to be as immediate as possible.

That issue has largely been mitigated by a new generation of edge computing technology: infrastructure installed in facilities with the processing power demanded by these compute-intensive workloads.

There are now many companies, like FogHorn, Hank, Brain Box, to name a few, that use Edge AI technology that creates new possibilities to digitally transform building operations. This includes advanced technology (known as Edgification) to optimize AI models to run efficiently on low-cost edge computing devices. By closing the on-premises capability gap, edge devices provide an architectural component important for achieving the goal of running a building as efficiently and effectively as possible.

Choosing between the cloud and Edge AI

With the availability of Edge AI, building managers inevitably face the question of whether to deploy AI on-premises or in the cloud. For those facing this question, there are some simple rules of thumb to consider.

Edge AI is best when:

Actions need to be executed in real-time, or close to it. Smart automation systems that detect operational problems and automatically alert or respond to them tend to work best when the latency is minimized as much as possible.

Local control of a system is required. Turning off a machine or adjusting a control system from the cloud often runs into security and latency challenges. There are limitations to data transit and storage costs. Take for example, a video monitoring system in which high-fidelity images from multiple cameras are analyzed by a computer vision AI model, a popular AI application. Sending to and storing all that data in the cloud can quickly become cost prohibitive.

The cloud may be better when:

Completing rigorous data analysis. Often building managers want a deeper understanding of how they’re operating based on AI analytics, or to run simulation exercises on a ‘digital twin’ version of their facilities. That kind of data analysis typically doesn’t need to happen in real time, so it’s best executed in the cloud, where the managers can harness at any scale the most powerful hardware and software tools for the job.

A combination of both may be best when the enterprise is running multiple buildings and correlating information between them. The cloud allows for a centralized data clearinghouse and command center. As a practical matter, a hybrid approach is typically employed where some initial processing in the individual buildings happens through Edge AI and then cloud AI is run on the aggregated data from multiple buildings, possibly combining other data sources.

A digital twin manifestation of the building would further extend the building operators' capability to access all operational data remotely.

A combination of building automation and AI would further support a self-operating building that requires little to no human intervention. There are other advantages to using AI apart from a remote operation. AI would also be able to most efficiently maintain balanced thermal equilibrium36 in a building under any circumstances while at the same time ensuring occupant comfort, saving money, and reducing the carbon footprint.

There are still barriers to smart buildings. They include a general mistrust of artificial intelligence and the significantly higher cost of deploying AI-powered platforms. While there is some progress, there is still some work to be done to integrate protocols for various types of equipment used in smart buildings. Machine learning algorithms and more advanced statistical algorithms are also being developed to perform increasingly complex learning processes. Notwithstanding, the challenges, the use of artificial intelligence in building management is a strong trend, and the adoption of artificially artificial AI-powered BMS platforms is projected to increase, especially in new design and construction.

Due to the widespread of cloud-based applications and smart building technologies, which are now linking cyber and physical infrastructure, cybersecurity controls are increasingly essential to protect occupants, building infrastructure, and smart building functions against cyberattacks. Blueprint Chapter 4 – Cybersecurity Considerations explores this issue further.