Development of an IoT-Based Learning Media on a Miniature HVAC System for Operating Rooms

Abstract

Due to its complexity and high cost, a full-scale HVAC system is difficult to implement in educational settings, hence a miniature model is needed to represent its working principles. This study aims to design an IoT-based miniature HVAC system as an affordable and interactive learning medium. The miniature was developed using an ESP32 microcontroller as the main controller because of its dual-core processing capability, integrated Wi-Fi and Bluetooth connectivity, and wide support for sensors and actuators. The ESP32 processes data from the DHT22 (temperature & humidity), MPX5010DP (air pressure), PMS5003 (air quality), and PIR (motion) sensors, then controls actuators including blower fans, exhaust fans, a PTC heater, and a mini air conditioner. The system can be operated both automatically and manually via the Blynk application, which provides real-time monitoring of environmental parameters. The research employed the Research and Development (R&D) method through stages of hardware–software design, expert validation, and functional testing using the System Usability Scale (SUS). Expert validation results showed the media to be in the very feasible category (≥82%), while the SUS test produced an average score of 75.1, categorized as good, indicating that the system is user-friendly and well-accepted. In conclusion, this IoT-based HVAC miniature successfully represents the core functions of a real HVAC system at a smaller scale and economical cost.