A Dual-Station IoT Monitoring System for Assessing Indoor Air Quality Variations Induced by FDM 3D Printing in Non-Industrial Environments

The widespread adoption of desktop Fused Deposition Modeling (FDM) 3D printers in domestic environments has introduced new challenges related to indoor air quality and environmental comfort. As these devices increasingly become part of smart home ecosystems, understanding their impact on the surrounding indoor environment is essential for ensuring healthy and sustainable living conditions. This paper presents a low-cost dual-station Internet of Things (IoT)-based monitoring architecture designed to assess the environmental effects of FDM 3D printing activities in non-industrial settings. The proposed system consists of two wireless measurement stations based on ESP32 microcontrollers and synchronized through the ESP-NOW communication protocol. Each station integrates sensors for air temperature, relative humidity, carbon dioxide (CO2), total volatile organic compounds (TVOC), and particulate matter (PM1.0, PM2.5, and PM10), enabling simultaneous multi-point monitoring of indoor environmental conditions. Experimental tests were conducted using an Ultimaker 3 Extended printer processing PETG filament. Two printing configurations characterized by different printing durations and material volumes were investigated and compared with non-printing environmental conditions. The results highlighted measurable variations in thermal parameters and volatile organic compound concentrations during the printing process, while the distributed monitoring approach revealed spatial differences in pollutant propagation within the monitored environment. The proposed solution represents a scalable and cost-effective platform for indoor environmental monitoring, supporting the development of data-driven strategies for smart living environments and non-industrial air quality assessment.