# Ensuring Energy Efficiency of Air Quality Monitoring Systems Based on Internet of Things Technology
## 4 Results
Each protocol has its own characteristics that affect power consumption, transmission range, bandwidth, and other variables (Table 3). Among the main data transfer protocols used in such systems, Wi-Fi provides high transfer speeds but is characterized by significant power consumption and a limited range. It is most suitable for stationary devices with a constant power supply. Bluetooth is more energy-efficient but has a short transmission range. This protocol is often used to transfer data between devices in close proximity. Zigbee, in turn, provides low power consumption and the ability to create networks with many sensors, making it effective for applications involving low-power monitoring systems. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Model** & **Measured Parameters** & **Data Transfer Method** & **Power Supply** & **Features** & **Price (UAH/USD *)** \\ \hline
104.ua Air & CO2, temperature, humidity & Wi-Fi & Constant power (USB) & Stylish design with LED display; audible alerts for exceeding CO2 standards; the ability to integrate into the Smart Home system. & 1450/\(\sim\)35 \\ \hline SaveEcoSensor & PM2.5, PM10, temperature, humidity & Wi-Fi & Constant power (USB) & The data are available through the SaveEcoBot platform; the ability to view the measurement history; integration with other environmental services. & \\ \hline Ajax LifeQuality & CO2, temperature, humidity & Jeweller (proprietary protocol) & Battery (3x AAA, up to 3 years) & Integration with Ajax security systems; long battery life; mobile conditions about changes in air parameters. & 8299/\(\sim\)200 \\ \hline AirHome & CO2, PM2.5, temperature, humidity & Wi-Fi & Constant power (USB) & Possibility of remote monitoring through a mobile application and setting thresholds for notifications. & 2350/\(\sim\)57 \\ \hline Smart Air & CO2, PM2.5, PM10, TVOC, temperature, humidity & Wi-Fi, Zigbee, BLE & Permanent power supply (USB) or battery & Integration with smart home systems; real-time data display; automation of climate systems. & 650/\(\sim\)16 \\ \hline \hline \end{tabular}  
* Prices converted at an approximate exchange rate of USD 1 \(\approx\) UAH 41.5 (2025).  
\end{table} 
Table 2: Comparative table of the most popular air quality sensor models in Ukraine. LoRaWAN is characterized by low power consumption and a long transmission range, making it an ideal choice for mobile sensors and large-scale networks. Another important protocol is NB-IoT, developed on the basis of cellular networks; this provides low power consumption and a significant range, so it is suitable for the mass deployment of IoT devices [27]. When choosing a data transfer protocol from the point of view of energy efficiency, several criteria should be taken into account. Power consumption in transmit and receive modes is one of the most important parameters, as lower power consumption allows the devices to run on battery power for longer. Transmission range is particularly important for remote sensors that require stable communication over long distances. Bandwidth determines the rate of data transmission and can affect the frequency of measurements, which is important for systems that require operational monitoring. Networking capabilities, such as support for data routing and the creation of sensor networks, are also of great importance. Finally, the cost of the modules and the licenses needed to use the protocol is an additional criterion that must be considered when designing energy-efficient IoT solutions. Strategies to reduce energy consumption during data transmission are important to ensure the effectiveness of IoT air quality monitoring systems. One of the key strategies is to optimize data frequency. In cases where the requirements of measurement accuracy allow for reducing the transmission frequency, this strategy contributes to a significant reduction in energy consumption and an increase in the autonomy of devices. Using device sleep patterns is another effective way of reducing energy consumption.