# Intelligent Thermal Comfort Controlling System for Buildings Based on IoT and AI
## 3 Material and Methods
### Hardware Devices and Data Collection  
The monitoring system of the method includes a sensor module consisting of a temperature sensor, a humidity sensor, and a wind speed sensor. The module is placed in the area to be measured indoors, and is used to collect air temperature, relative air humidity, and air velocity at the measurement points. The module of the temperature sensor also contains the wet bulb globe thermometer (WBGT) for radiant temperature. JTR-10-C WBGT' is used for monitoring the globe radiant temperature and indoor air temperature at the same time. The collected indoor air temperature can be used for mutual calibration with the figure monitored by temperature thermometer. In theory, there are also formulas to convert wet bulb globe thermometer and air temperature for the figure of average radiant temperature (Tr). Here, they don't need to be manually calculated under the convenience of this device. After collecting, the data is sent to a receiving and storage module via a wireless transmitter, and then stored on the computer used. Among them, each module is connected to the power supply equipment to ensure its normal and stable use. The air temperature and humidity sensor use an integrated chip, which can directly output temperature and humidity digital signals. The measurement temperature range is \(-20\) to \(60\)\({}^{\circ}\) C with the accuracy \(\pm\) 0.5 \({}^{\circ}\) C, and the humidity measurement range is 0 to 100%. The wind speed sensor uses a pulsed wind cup anemometer, and the measurement wind speed range is 0 to 50 m/s. The sensor can collect real-time data in the room and then store it in the analysis system. The parameters of the collected data are classified as follows: air temperature (Ta), average radiant temperature (Tr), air speed (Va), relative humidity (HR), metabolic rate (met), and clothing condition (clo). Figure 5 shows the workflow of data collection and general procedure.  
Many of the test instruments and sensors used have standardized data transmission protocols, which are common hardware sensors for the Internet of Things. It is more accurate and scientific from data acquisition to storage. The hardware includes induction acquisition module, light intensity  
Figure 5: Data Collection and Procedure.  
sensor, wind speed sensor, temperature sensor, humidity sensor. The control module includes an input terminal, an output terminal, and an interface and a power supply module for connecting various IoT devices. During the measurement and data collection phase, after the multi-parameter sensor group is deployed indoors, the devices and sensors are activated. Then, the measurement command is sent. The measurement command is transmitted to the multi-parameter sensor group through the gateway and the routing node in turn and stored to the computer hardware. The collected data is stored in a CSV (comma-separated values) format by an automated program to facilitate later data processing. In the control phase, after receiving the data, the gateway sends the data to the control module, and the controller operates according to the command and returns the control result.  
The experiment started on September 1, 2019 and ended on September 30, 2019, for a total of 30 days. The system starts daily from 8:00 AM to 6:00 PM. Parameters are recorded every 10 minutes, including air temperature (Ta), average radiant temperature (Tr), air speed (Va), relative humidity (HR), metabolic rate (met), and clothing condition (clo). The collected data is divided into two groups: training group and validation group. The experimental site was located in a standard-sized room in Qingdao, China. All IoT sensors used comply with industrial design standards.  
The device has a simple structure, low production cost, and wide application range. At the same time, the system runs stably, which can ensure the accuracy of the collected data and real-time transmission and storage.