Selecting Smart Building Sensors


Rigado Sensor Partners

When it comes to selecting wireless sensors and devices for your Smart Building initiative, the path to decision is often not straightforward. It’s easy to feel lost among the myriad of existing and new devices, supporting a variety of wireless protocols.

Having clearly defined what data points are necessary to support your end Smart Building application(s) is, of course, the main prerequisite. And with some additional preparation (and a little advice) it’s possible to make the selection process significantly more straightforward. With that said, let’s dive in!

What to Know About Smart Building Sensors

Having answers to the following questions will help define what sensor hardware is right for your solution today, and into the future.

Use Case(s)
  • What physical/environmental data is necessary to support your solution goal? (i.e. room presence, temperature)
  • How frequently does data need to be sent from sensor to gateway and on to the cloud?
  • How much latency is acceptable?
  • Are there future use cases / applications that this system should support?
  • Is there a minimum acceptable device battery life?
Installation
  • What existing system protocol(s), if any, must be supported?
  • How many total sensors are required for each room / space / floor / deployment?
  • Are there installation constraints that must be considered? (i.e. small footprint, mounting style)
  • Are there form factor considerations? (i.e. holes for lanyard or zip ties, digital display)
  • Are there environmental or usage considerations requiring IP-rated enclosures? (i.e. extreme temperature, dust)
Budget
  • What is the project budget for end device hardware?
  • Who will install the sensors and provide management services?
  • Will the system remain cost-effective as new use cases emerge?

Types of Sensors

Today, wireless sensors and devices exist to collect nearly any desired physical or environmental data points. However, in a wireless edge network, all devices need to be protocol interoperable at the gateway level. With the Rigado Cascade IoT gateway that means devices that support Bluetooth standard protocols and custom profiles, Wirepas Mesh, Zigbee and Thread, Wi-Fi, Ethernet & TCP/IP, or USB 2.0.

It’s important to keep in mind that technology and protocols, particularly in the IoT space, are iterated upon and improved at a rapid pace. An informed perspective on where the technology and markets are moving is invaluable for future-proofing your solution.

Following are some basic sensor types regularly utilized in Smart Building solutions:

Temperature

Temperature sensors measure ambient temperature within device proximity. Typically in a small form factor, temperature sensors can be placed nearly anywhere, giving you the ability to identify and monitor spaces not evenly heated or cooled. With HVAC system integration, automated adjustments can help fine-tune indoor climate as changes to the environment dictate. This level of data visibility and control can help optimize energy management and drive large-scale cost savings. At the same time building tenants benefit with a consistent, comfortable environment leading to higher productivity, satisfaction, etc.

In certain Smart Building environments, temperature sensors can also be used in specialized climate areas such as server rooms, to identify and alert when air intake or outtake temperature for an individual server rack exceeds expected limits.

There are also a range of specialized temperature sensors designed for cold-chain temperature monitoring (e.g. food safety, medicines), which may have very specific measurement and data logging capabilities. A good example is CDC-compliant data loggers for vaccine-monitoring, ensuring that medicines remain safe to administer.

Humidity

Often coupled with a temperature sensor on the same device, humidity sensors monitor the amount of moisture in the air. Humidity management plays a large role in building climate and tenant comfort. Too little humidity results in discomfort due to dryness in the nose, throat or eyes, as well as the air feeling colder than it is. Data from humidity sensors can be used to monitor and control HVAC systems to ensure that humidity is kept at a safe and comfortable level for people and equipment.

Humidity monitoring is also important in maintaining optimal climate conditions in areas with sensitive and expensive equipment, such as research laboratories and high-value server rooms. Pair monitoring with alerting to proactively address excursion events.

Motion / Occupancy

Motion sensors and occupancy sensors are terms often used interchangeably. These sensors can detect motion or presence by using active detection, passive detection, or a combination of both. Active detection sensors emit a signal and look for changes to the reflected signal to determine if there is motion. Passive sensors detect changes in the infrared spectrum, which occurs when a person is within the field of view of the sensor (a person emits heat which is an infrared signal).

Motion and occupancy sensors have a variety of uses in a Smart Building environment. Presence data can simplify the process of conference room or hot-desk scheduling, improving employee productivity. Occupancy data can provide insight into heavily trafficked workspace areas and can be analyzed over time to determine improvements to workspace efficiency. Data and analytics from these sensors can be tied into smart lighting or HVAC control systems leading to cost savings.

Window / Door

Also referred to as a contact sensor, these devices come in two parts and detect when the two have been separated. Typically, one part would be installed on a door, bay or window frame, and the other on the door or window, placed next to the other piece when in a closed position. When the door or window is opened the two pieces separate and the sensor detects the event.

Contact sensor data can be used for security and accountability, and to provide insight into office traffic, how often certain rooms are used, or how office climate is affected by door placement or window ventilation.

Gas / Air quality

Air quality sensors come in a wide variety of types and form factors. Common to Smart Building solutions are carbon dioxide (CO2) and carbon monoxide (CO) sensors. Increased carbon dioxide levels can occur in crowded spaces, or due to poor or blocked ventilation – often resulting in a feeling of stuffiness and, in some cases, tenant illness. Data from the CO2 sensor can used to adjust the ventilation system. Pair monitoring with alerting to proactively address excursion events.

Carbon monoxide (CO) monitors are often used in parking garages and can detect and alert if there are unsafe levels of Carbon Monoxide in the air.

Optical

Optical (light) sensors measure the amount of illumination in an area and are often integrated with motion sensors that trigger lighting in a room or area when presence is detected. Illumination sensors can be used to monitor and automatically adjust lighting levels as the sun rises or sets, on bright or cloudy days, or if the shades are up or down. Having the proper illumination level in a work environment can reduce the risk of eye strain, headaches and glare and provide a more comfortable environment.

Accelerometer

Accelerometers are used to measure proper forces of acceleration and vibration in a device or system. When an accelerometer is mounted to an asset it can determine if the item is being used – or provide insight as to when the last time the item was activated. Accelerometers can be used to track when shared equipment is in use, and when coupled with proximity sensing (see Asset Tag), can also indicate in what zone or area the asset is located.

Asset Tag / Beacon

Asset Tags, sometimes referred to as beacons, indicate the proximity of an item by consistently sending a transmission that is picked up by nearby receivers. The distance from the beacon to a set of receivers (e.g. gateways) can be approximated based on the received signal strength, and tell if a beacon has entered or left a vicinity. Attaching a beacon to an asset allows its movement to be tracked throughout a building or supply chain.

These tags come in many different form factors for different uses, including as wearables such as employee badges. Often additional features like buttons and accelerometers are built into asset tags to provide additional value. The relative simplicity of this type of sensor has enabled a robust device market and a growing number of manufacturers.

Moving Forward

While the above sensor types list is by no means comprehensive, we hope it provides a starting point for your Smart Building device considerations. For a list of sensors and devices that we have successfully integrated with Rigado solutions and gateways, along with some key features, visit our Integrated Sensors and Devices page.

Having worked over the past nine years with 300+ customers and millions of wireless devices we offer the following advice when selecting sensors for Smart Building solutions:

  • Purchasing an off-the-shelf sensor (versus designing and building your own custom device) will very likely save you money, time and resources on your path from pilot to production. Manufacturing high-quality wireless sensors and devices requires a significant investment in wireless engineering design and development, which is very often not the core competency of enterprise solution providers.
  • For cost-sensitive applications, a Bluetooth sensor infrastructure is arguably the most economic approach. Its proliferation in IoT devices is steadily driving down the cost of the technology. And the protocol’s ubiquity makes integrating mobile devices easy and intuitive. Learn more about Bluetooth in commercial IoT use cases ⟶
  • Sensors and devices that support mesh networks like Bluetooth 5 Mesh and Wirepas are excellent for use cases like Smart Lighting and Asset Tracking. They increase network intelligence and coverage area without sacrificing latency. However, they are often more resource-intensive to architect and deploy. For that reason, we recommend that teams have a dedicated in-house engineering team – or work with an IoT integration partner – to support large-scale mesh networking solutions.

Lastly, it’s worth noting that an edge-as-a-service model like Rigado Cascade can take up-front sensor hardware and ongoing maintenance costs off your hands completely. Bundling sensor investment, integration and support into an annual subscription can significantly reduce solution complexity and total cost of ownership. Learn more about Rigado Cascade Edge-as-a-Service ⟶

Ready to take the next step? We can help. Connect with our solutions team today!