3 Candymill Lane, Hamilton, ML3 0FD

Iot White Paper

Digitally enhanced infrastructure layers technologies that, together, allow a building to be monitored, managed, and controlled more efficiently. Buildings can be optimised with improvements to energy efficiency, safety, occupant satisfaction and wellness. Importantly, buildings will require technology solutions in order to bring themselves into compliance with net zero legislation, and with concomitant alterations to the tax regime.
At the edge of digitally enhanced infrastructure are sensors and actuators. These interact with the environment in and around the building, and will be discussed in this paper both in terms of use cases and capabilities. Through wired or wireless connections, they connect to components, and various options for wireless connection are also discussed in the following pages.

System designers, installers, integrators, and to some extent owner-operators, should be aware of the practical applications of IoT in buildings, as well as the range of available sensor types and technology options, as building systems continue the transition from on-site BMS to cloud-based software-as-a-service alternatives. This paper is not comprehensive. It is intended as an abbreviated topic summary of the intelligence that clients have available through our consultancy service.

[um_loggedin]
Sensors and Actuators: What’s the Difference?

IoT – the Internet of Things – is a network of physical objects that contain embedded technology to communicate and sense or interact with the external environment. In practice, there is no single Internet of Things, but any network and technology that provides this functionality could be considered IoT. A clear distinction must be made between IoT sensors and actuators which fulfil distinctly different functions. Some devices may have both capabilities, but put simply, sensors collect data to (a) provide insight, (b) enable control, (c) generate automated tasks and workflow, and (d) trigger change.

Actuators on the other hand are meant to turn devices on and off, to open and close valves, and to enhance the capability of ‘dumb’ systems and devices through the combination of the environmental awareness, the application of control logic, and the control of an actual device or system.

There are sensors with generic capabilities which may be able to provide inputs and insight across a widely deployed estate: we will go on to discuss possible use cases but, in brief, these could be deployed in apartments, large amenity spaces, reception areas, and used to gather data and provide insight.

Additionally, there are sensors which can provide very specific functionality and drive specific outcomes: for example, wellness, space utilisation, and specific tasks of the sort that we outline in the coming pages. (It should be remembered that this paper does not focus specifically on sensor functionality, and only gives a few examples from a considerably greater range of available options.)

IoT Sensors and Actuators will provide capability and insight, particularly when combined with intuitive visualisation and analytics, as well as decision and control logic.

Connectivity: In Brief

A variety of connectivity options and sensor types can be chosen and deployed depending on the building or development in question. Key considerations ought to be:

  • New vs. retrofit
  • Cabling
  • Power (Mains, PoE, Battery)
  • Format and destination of data
  • Real time requirement
  • Frequency of communication and volume of data

For the majority of requirements, LoRaWAN will provide the most attractive combination of the factors above and is proposed as the default sensor type. LoRaWAN, as a low power radio technology, is near real-time and some communications may be lost or may need to be repeated. This must inform the decision making. Where there is a requirement which cannot be met by a LoRaWAN sensor, an alternative should be chosen to meet the specific requirement.

 

Connectivity: In Depth

For many IoT sensors it is desirable to have low power consumption to allow sensors to be battery powered and operate for many years, as it may be uneconomic to provide a power connection. Even powered devices can benefit from using low power wide area network (LPWAN) data connectivity as a common method of gathering data and controlling devices due to the low infrastructure costs.

The primary technology focus for IoT network provision is a wireless technology called LoRaWAN – a global standard for LPWAN technology. Using a common protocol and standard allows the use of the same wireless technology infrastructure to be used for multiple purposes and makes it possible to choose from a global supply chain of sensors and actuators. LoRaWAN operates in the 868MHz frequency band, enabling excellent building penetration and coverage. Large-scale developments will be able to be covered with a small number of LoRaWAN gateways, providing coverage throughout.

There are other technologies which could potentially be considered, of course. Sigfox, a proprietary solution operating in the same frequency band as LoRaWAN, but with limited payload and message frequency, relies on a service provider to provide the network services. Sigfox would be willing to have gateways deployed on a development, but there is only one operator in the UK. So, Sigfox has a limited development community and lags somewhat behind LoRaWAN in terms of sensor availability and deployment.

Narrow band IoT (NB-IoT) is a mobile operator proposition and, by definition, relies on mobile signal coverage. Vodafone is the key player in NB-IoT in the UK at present. Services and commercially available hardware is less available than for LoRaWAN services at present. This may change over time, however.

Some sensors may be connected over WiFi. Due to the power requirements of WiFi standards, however, any WiFi sensors will typically require external power. This may not be too much of an issue if the sensor itself is quite power hungry and would require external power (for example: laser, many air quality sensors, or devices that actively need to scan or open and close things physically). Low latency sensors may also be better served on WiFi or Ethernet, given the real-time nature of those technologies.

Ethernet connected sensors will, by definition, require cabling and a PoE LAN port for Ethernet data backhaul. Low latency communication and the ability to send higher bandwidth data streams may be beneficial for specialist applications like video-based people counting.

Building management systems will have some sensor connectivity through legacy standard protocols and connectivity such as BACnet and Modbus. These are valid in that they are being used for building control purposes, but will come with limitations in terms of cabling, location, quantities and cost and will also require power.

 

Generic Sensors

There are a number of generic data sets which will provide valuable insight, as well as trigger points for controls. Data sets can be stored for ad hoc or periodic historical analysis. Developers may want to have more than one sensor in a large communal space to get a view from different parts of that large space. But the basic insights that can be gained from generic sensor types are outlined below, giving some idea of potential applications.

 

Temperature

Provides current temperature in a room or location

  • Switching heating/cooling on or off – either as a single factor or combined with others (e.g. closed doors/windows and/or room occupancy) à potential for lowering energy consumption and CO2/cost.
  • Can show long term under/overheating
  • Could form part of a multi-factor wellness indicator

 

Humidity

Provides current relative humidity in a room or location:

  • Comfort / wellbeing factor, part of air quality
  • May indicate lack of ventilation
  • May provide input into ventilation control
  • May indicate damp risk

 

CO2

Provides current CO2 level:

  • Comfort / wellbeing factor, part of air quality
  • May indicate lack of ventilation
  • May provide input into ventilation control

 

Light level

Detecting current light level:

  • Potential input for smart lighting daylight harvesting (dynamic dimming)
  • Low light detection (if ‘dumb’ lighting)
  • Dusk/dawn settings
  • Combined with occupancy on/off

 

Occupancy / Presence (PIR):

Detecting movement of people/presence (note that this is not people counting, but has the same functionality as a PIR sensor for a home alarm):

  • Potential input for lighting, HVAC, Heating
  • Utilisation of amenities and public spaces
  • Situational awareness (i.e. what apartments are occupied) – fire safety enhancement

 

Noise

Reporting noise levels (note that this sensor does not ‘listen’ like an Alexa, it just reports sound level in dB without being aware whether it is music, spoken word or noise):

  • Potential detection of antisocial behaviour
  • Detection of ambient noise and event noise
Specialised Sensors

Other sensors are available that have more specialist capabilities, for example people counting and presence detection. There are a number of different ways that this can be achieved – some CCTV cameras have people counting capabilities (in/out) using on-board video analytics. Some sensors scan using laser or radar. There is a trade-off between accuracy and cost of the sensors, but, placed in strategic locations, a smaller number of highly accurate sensors will provide significant insight, helping with space optimisation and, in residential developments, the placement of amenities. These sensors require power – PoE or mains – due to the active scanning requirement.

Another example would be electricity/water metering. Current electricity and water meters require a separate wired infrastructure to provide utilisation data. Using LoRaWAN could overcome the requirement for the additional wired infrastructure. Meter data can be presented in database/table format for onward processing, but is then also available for analytics.

One of our partners has been working on a specific fire door sensor which can detect potential fire risks from doors left open or ajar, providing enhanced performance for fire door compliance with a near real-time view potentially on every fire door within a development. Similar sensors can be placed at doors and windows; these sensors can provide input into HVAC/MVHR control if required.

Given the fact that some developments have rooftop space for their residents, there may be a requirement to measure local data on site (as MetOffice data will be gathered at a station which may be some distance away, and high-rise buildings potentially affect on-site wind speeds). Wind speed data can be used to provide data needed to comply with health and safety obligations and other data (for example, temperature) may be used for resident information or as an indicator when gritting is required in winter.

Car parking sensors could be used to show through an app when certain high-value spaces (for example, EV-charging) are used or available; in offices, it can be used in tandem with BIM to alert reception of an employee’s arrival and prepare a brief for them, or their preferred coffee or tea when they enter in the morning.

Sensors can also be used to monitor pipes for temperature, or leak detection. Temperature sensors are designed to measure the water temperature in pipes using external pipe-mounted temperature probes. By continuously monitoring this, it is possible to show compliance with legionella regulations, reduce risk and quickly identify issues for resolution.

Finally, there are a number of options available for bin-level monitoring; the size and shape of the bin itself would be an important deciding factor in which sensor to use. And for monitoring the air quality in industrial environments via measurements of volatile organic compounds and particulate matter (dust). It may also be possible, in cases where plant equipment does not have native integrated temperature and vibration sensors, to provide an external, non-invasive view of the equipment using industrial sensors that can detect and report vibration, temperature, smoke, and so on.[/um_loggedin]

Leave a comment