Environmental quality monitoring in indoor spaces directly impacts occupant health and influences energy consumption efficiency. Smart IoT sensors enable this process by measuring various parameters in indoor environments, including temperature, humidity, air quality and illuminance. In this study, we utilized both commercially available sensors and an internally developed device, the Promet&o multisensor, to conduct our measurements. To support this system, the development of a software platform was required. This platform is designed to efficiently store the collected data, calculate indoor environmental comfort indexes, and provide capabilities for data visualization and analysis. Due to the high volume of incoming data from IoT sensors, the wide variety of sensors, and the location of the networks, exploring techniques to preprocess, and to perform comfort indexes calculation should be an important point of attention.