IoT Sensing of Indoor Air Quality – Is This a Future?
What is IoT sensing technology and how can it be applied to monitoring indoor air quality? Why is it important to monitor indoor air quality? What are the benefits of IoT sensing technology? What are the other related topics of IoT sensing? Are there some available commercial products in the market? How much is it? Is this a real future?
Here, we would like to answer for all these uncertain questions…
Emerging IoT sensing technology and indoor air quality
The Internet of Things (IoT), which allows mundane “things” or objects to be connected each other over the internet infrastructure, has been applied to many different sectors of our daily lives. These emerging IoT technologies provide more and more informative benefits to people, allowing them to be easily aware of different surrounding contexts and take an optimal behavior.
In developed countries, most people spend 90% of their time indoors [1]. In fact, each day we eat, sleep, commute, work, shop and/or spend time in different enclosed environments, which again proposes the importance on maintaining good IEQ(Indoor Environmental Quality) for human [2]. In particular, one of the most critical components of an indoor environment is maintaining a good indoor air quality (IAQ), i.e. fresh and clean air for better human health and comfort. According to the statistical data from Environmental Protection Agency (EPA), indoor air is two to five times more polluted than the outdoor air [3]. Moreover, health risks of human occurred by exposure to air pollution indoors may be greater than outdoors [4].
IoT sensing technologies applied to monitoring IAQ
In this background, many documentations related to IAQ sensing & monitoring techniques have been proposed recently [5-20]. Some of them included IoT architecture as a monitoring solution, which enables better communication in-between occupants and devices [5-10]. The others are more focused on building a wireless network system or developing multi-sensor stations to monitor indoor environments, which can also have a strong connection with IoT sensing technologies [11-24]. One popular trend in monitoring IAQ in buildings is to develop a WSN (Wireless Sensor Network) system, which is also a subset of IoT [11-17]. This topic can be linked to real-time continuous IAQ monitoring or low-cost IAQ sensors, which allows large-scale deployment of WSN system to be feasible in building sector.
Along with this trend, some researchers have been focused on developing multi-sensor IEQ monitoring systems, which measures indoor environmental indicators (e.g. air temperature, CO₂ concentration, relative humidity, and particles) and validated their performance and accuracy by conducting chamber or field tests [7, 17-21]. Especially, implementation of low-cost sensors with advanced IoT technologies has opened a future expansion in wide-scale monitoring IAQ in buildings [22-24]. In brief, IoT sensing technologies has a big potential to transform current approaches for IAQ monitoring and even for building HVAC controls, while providing better environments to building occupants. In a near future, low-cost IAQ monitors equipped with IoT sensing techniques will collect the continuous and accurate data from whole building and serve prompt information for occupants and building engineers to improve the environmental quality indoors and occupants’ health at the same time.
IEQ monitoring products in market including IAQ indicators
Some commercial products monitoring indoor environments using IoT technologies are available in today’s market (Figure 1). Most of the products has great potential since it is mostly within affordable price range (around USD 250) while considering acceptable accuracy in measuring indoor environment. Moreno et al (2019) reviewed low-cost IAQ monitors and tested the performance of one well-known IEQ monitoring device named Foobot. They concluded as in a near future, low-cost IAQ monitors make affordable simultaneous monitoring of different spaces strengthening data collection to better understand indoor pollution and eventually improving occupants’ well-being [24].
Figure 1. Commercial IAQ monitoring devices in nowadays market
In brief, continuous monitoring on IAQ inside a building will become necessary component in terms of not only maintaining good indoor environments for occupants but also saving building energy by knowing accurate occupants’ demand. Alongside, IoT sensing technologies and growing market of low-cost sensors will make the real-time monitoring of IAQ much easier and affordable.
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