Indoor Environmental Quality (IEQ), which encompasses thermal comfort, indoor-air quality, visual comfort, and acoustic comfort, directly influences health, well-being, and productivity inside buildings. This narrative review synthesises peer-reviewed studies retrieved from Scopus and Web of Science (2015 to June 2025) to assess how Internet-of-Things (IoT) technologies are being used to sense, analyse, and actively regulate the four IEQ domains. The evidence shows that IoT-enabled systems consistently outperform conventional controls: they narrow temperature and humidity fluctuations, deliver ventilation precisely when pollutant loads rise, modulate daylight and electric lighting to balance brightness and glare, and dynamically mask or cancel disruptive noise, all of which translate into measurably healthier, more energy-efficient spaces and higher occupant-satisfaction ratings. Yet adoption is still tempered by sensor drift, platform incompatibilities, cybersecurity vulnerabilities, and the e-waste and standby-energy burdens of dense device networks. Overcoming these barriers will require durable, self‐calibrating sensors, open communication standards, privacy-by-design governance, and circular deployment models, supported by long-term field trials and interdisciplinary collaboration among building scientists, computer engineers, and behavioural researchers. Taken together, the findings confirm IoT’s substantial promise for next-generation smart and sustainable buildings while charting a clear agenda for future research and practice.
Ghiai et al. (Wed,) studied this question.