The role of IoT in energy management and smart buildings
Why most buildings aren’t actually very smart, and moving to demand-based heating and cooling
Heating in individual rooms is often controlled using tradition thermostatic radiator valve (TRV) controls, which have several limitations. They can only turn the radiator off when the room reaches the setting on the valve (often not a specific temperature). When a window is opened, the temperature drops and the thermostat tries to maintain the preset temperature even though there is continuous heat-loss to the outside. This leads to unnecessary and wasteful heating.
Why is the window open? One reason is TRV controls do not take sunlight into account. Sunlight is important because it can make people feel warmer, especially if it is direct and intense. Sunlight contains both visible light and infrared radiation that can heat up objects, and people, it shines on. As a result, a room on the sunny side of a building will feel warmer than a room on the shady side, all else being equal. In short, sunlight can make a room feel warmer than it actually is.
Neither do TRV controls take occupancy into account. Does the room need to be heated if its unoccupied. Probably not.
Cooling has the same issues. Set the air-con to 18 degrees on a summers day and open a window and you’ve basically set up the system to waste a lot of energy trying to achieve an impossible task.
IoT-based systems can use sensors to detect whether a room is occupied or whether windows are open, and turn the radiators/air-con off accordingly. This leads to better control and energy efficiency, preventing unnecessary heating and cooling.
More broadly, IoT technology enables the collection of data from various sensors within the building, such as temperature, humidity, CO2 levels (which is a useful proxy for air quality), occupancy, and external weather conditions.
Such sensors are relatively inexpensive, and, with low data-rate wireless technologies such as LoRaWAN, they can be deployed in large numbers. Some sensors use energy harvesting technology and can transmit data without the need for batteries or wires.
These additional data points provide a much more detailed and accurate picture of the building's environment, allowing for better control and monitoring of the HVAC system. Compare this to a traditional HVAC system where there may only be one or a few thermostats that control the entire system.
IOT-based systems also allow you to assess the building’s performance over time. Traditional HVAC systems often have no memory of past activity because they rely on simple on/off or preset schedules, but IoT systems keep a continuous record of sensor data and activity, so you can look back at performance in different weather conditions, seasons, and even extreme weather events.
By analysing this data, these systems can optimise HVAC settings to minimise energy waste and improve overall building efficiency. This type of system can also provide insights into occupancy patterns and other environmental conditions that can inform decisions about building design, energy usage, and other related factors.
Combine this data with AI machine learning algorithms and location-specific weather forecasts and you can start to anticipate and adjust the HVAC settings to keep the temperature within comfort levels. For example, turning the heating on earlier than normal because you know it will take longer to bring the building up to a comfortable temperature.
In summary, Internet of Things (IoT) technology provides a solution to the limitations of traditional HVAC controls. IoT can be used to manage building HVAC systems in a more advanced and efficient way, including:
- Better control and monitoring: collecting data from various sensor types from more locations giving a much more detailed understanding of how the building uses energy.
- Energy efficiency: IoT-based controllers can adjust HVAC settings based this sensor data, reducing unnecessary energy usage and lowering utility bills.
- Integration with other building systems: By coordinating other building systems, such as security and lighting IoT can further reduce energy waste and improve overall building performance.
- Predictive programming: The ability to use past performance data to inform and continuously improve and optimise the system to maintain comfort levels in different weather conditions.
In short, IoT technology can help turn your existing fairly dumb building into a smart building, reducing energy costs and making your building more sustainable.