Leverage IoT for Energy Efficiency in Building Management

Internet of Things (IoT) technology offers building owners and operators a means to make their facilities more energy efficient. IoT technology is relatively new, only coming into widespread use within the last two decades. This network of interconnected devices, controllers, and systems is transforming built environments worldwide, and is the basis for building automation. The relationship between IoT and energy efficiency makes it a key element to creating intelligent built environments.

To evaluate the various devices used to automate systems, it is important to approach each according to how it is implemented within facilities using IoT technology. Energy efficiency is the primary purpose for automating systems, though in some cases this only occurs indirectly. For example, devices that monitor systems and equipment for maintenance issues often look at variations in energy consumption (particularly over-consumption) as an indicator of imminent failure. By identifying such issues, facility managers can enact predictive maintenance that indirectly reduces energy waste. 

The number of connected devices is growing exponentially, estimated to have reached over 50 billion in 2020. These IoT devices collect data once accumulated manually, or which had previously been too difficult to gather. Using IoT, energy efficiency becomes more achievable. Coupled with intelligent building management platforms (IBMP’s) that utilize artificial intelligence (AI) and machine learning (ML) algorithms, IoT technology offers one of the most promising solutions to reduce building energy usage. 

Leveraging IoT and BMS for Energy Efficiency

Energy efficiency is one of the many benefits of incorporating IoT into commercial buildings. IoT architecture includes sensors, actuators, cloud-based software and communication protocols, layered and controlled by a central building management system (BMS) that helps optimize systems, allowing them to communicate with each other and work together. 

IoT architecture is comprised of these components:

• Devices for monitoring and controlling energy use, which ideally identify areas of high consumption, actively control energy usage and indirectly control consumption based on factors such as occupancy, time of day, or other factors
• Location-based automatic controls that optimize controls in specific rooms or sections of a building, often in relation to time-based patterns, occupancy, weather or a variety of other factors
• Cloud-computing platforms that store data and run software, such as data analytics software that evaluates data
• Software applications that implement programmed energy efficiency strategies, such as integration software that interprets and communicates data between systems  

Using IoT, energy efficiency is driven by automation. With data gathered by smart sensors, a BMS can turn off lights in unoccupied rooms, reduce airflow in office buildings on weekends, or automatically close blinds when windows are exposed to direct sunlight. 

Energy-Saving IoT Devices

As physical hardware, IoT devices can be used to create greater energy efficiency throughout a building’s systems. 

These IoT devices include: 

Daylight Sensors

These use photocells to turn off or dim lighting based on the amount of available natural light. These photosensors can also be used to raise or lower blinds to optimize lighting. They typically achieve savings of more than 40%.

HVAC Controllers

HVAC controllers using IoT technology could reduce energy use by 24%, according to a 2011 study by Pacific Northwest National Laboratory (PNNL). Sensors measure various conditions within a building, using this data to regulate output within climate control systems. Smart controllers typically use predefined set points to determine actions and can be deployed at certain key points or throughout a building. Some more advanced sensors and controls implement machine learning (ML) algorithms to enact real-time changes.

HVAC Economizer Controls

Pulling in cool outside air to reduce the need for electrical cooling, economizers use sensors to measure either air temperature or heat and humidity to determine actions based on energy efficiency and occupant comfort. Economizers generate 57% energy savings on average, but savings can range from 22-90% depending on a variety of conditions. 

Lighting Controls

Lighting controls are comprised of both sensors and actuators that control lighting through the use of IoT. Energy efficiency results from lowering lighting output based on certain conditions. In a recent literature review focusing on lighting and controls in office environments that use IoT, energy efficiency estimates ranged widely. Results depended upon occupant behavior, control system type, patterns of activity, and other conditions. They showed between 17-94% savings from smart controls over manually controlled systems.

Occupancy Sensors 

Sensors that automatically turn on or off lights based on whether a room is occupied use infrared or ultrasonic technology, and can also be used for managing heating and cooling as well. Occupancy sensors generated from 3-60% in savings when used in lighting systems. Another study saw a 20% reduction in energy use from such sensors in HVAC systems. 

Smart Meters

When it comes to IoT, energy efficiency in buildings is built upon metering and monitoring. Smart meters are an essential tool in tracking energy use, generally offering immediate savings of about 10%. Over time, smart meters can deliver as much as 30 percent savings when utilized properly. Smart electric submeters can also track energy consumption according to tenants, systems, or even individual plugs. Submeters additionally help identify anomalies that indicate possible maintenance issues affecting energy consumption. 

Smart Thermostats

These enable remote monitoring and control of temperature within built environments. More advanced models can automatically provide analytics on energy usage that include reports showing amounts saved on a monthly basis. Two independent studies that looked at a top manufacturer of smart thermostats reported that customers saved 15% on cooling and 10-12% on heating on average. 

Variable Speed Drives

These are also known as adjustable speed drives, AC drives, inverter adjustable frequency drives, or variable frequency drives. In older buildings, fans in HVAC systems normally operate on a single speed, using dampers, throttles, and valves to control airflow. As these fans only operate at full speed, this results in significant energy wastage. Variable speed drives allow fans to operate at higher or lower speeds, according to the energy needed. Typically, variable speed drives reduce energy usage for heating and cooling in buildings between 24-35%. However, a 2017 study by the American Council for an Energy-Efficient Economy (ACEEE) estimated energy use savings between 15–50% from such controls. 

Sensors for Predictive Building Maintenance

Networks of IoT sensors that are connected to building systems, equipment, and other infrastructure help optimize building performance and save on energy costs. However, lowering energy expenses is just one way they promote efficiency. By proactively identifying issues before they become problems, facility managers are also able to get ahead of maintenance and avoid catastrophic system failures. 

IoT sensors used to deal with maintenance issues include:

• Early fault detection sensors that alert when unseen issues show a fault is imminent 
• Failure detection sensors that detect faults and disable machinery to prevent wider failures, which helps prevent injuries and downtime

While predictive maintenance offers energy efficiency indirectly, it creates savings in other areas. 

According to the US Department of Energy (DOE), predictive maintenance:

• Cuts downtime by 35-40%
• Decreases breakdowns by 70-75%
• Increases productivity by 20-25% 
• Offers ten times the return on investment
• Reduces maintenance costs by 25-30%

Some IoT technology can detect structural damage by measuring strain and cracks at key points. More directly, sensors used in predictive maintenance detect maintenance issues in energy-sucking systems like HVAC and lighting, reducing costs by keeping these systems working optimally. 

For Buildings IOT, energy efficiency is a key goal. For information about products and services we provide to optimize energy efficiency in buildings, contact our team of experts today.