Comparison Study of Automatic Room Humidifiers

Abstract

Maintaining optimal indoor humidity is essential for ensuring comfort, health, and air quality. This project presents a comparative study of two automated room humidifiers integrated with NodeMCU-based smart control. The first model utilizes an ultrasonic humidifier to generate fine mist silently, while the second model employs a mechanically operated system using a BO motor and crank mechanism to disperse water into the air. Both systems incorporate a DHT11 humidity sensor to monitor ambient conditions and activate humidification when required. The study evaluates each model based on parameters such as cost, efficiency, noise level, maintenance, and complexity. Results indicate that while the ultrasonic humidifier offers quiet and efficient performance, the mechanical humidifier serves as a cost-effective and faster alternative for basic applications. The analysis aids in selecting an appropriate humidification method based on user needs and environmental conditions.

Introduction

Maintaining optimal indoor humidity (40–60%) is essential for health, comfort, and protection of materials and electronics. Low humidity can cause respiratory issues, dry skin, eye irritation, and damage to wooden furniture or sensitive devices. To address this, the project designs and compares two automated smart humidifier models using NodeMCU (ESP8266) and DHT11 sensors for real-time humidity control.

Model 1: Ultrasonic Humidifier

• Uses ultrasonic vibrations to produce a fine mist.

• NodeMCU triggers the device via a relay when humidity drops below the set threshold.

• Advantages: Silent, compact, aesthetically suitable for modern spaces.

• Limitations: Requires distilled water and regular cleaning.

Model 2: Mechanical Humidifier

• Uses a BO motor and crank mechanism to splash water into the air.

• NodeMCU controls motor activation based on humidity readings.

• Advantages: Cost-effective, uses regular water, suitable for DIY setups.

• Limitations: Produces mechanical noise, higher maintenance due to moving parts.

Methodology:

• Both models use DHT11 for humidity monitoring and NodeMCU for automated control.

• Systems were tested for humidity regulation speed, energy consumption, noise, ease of use, and responsiveness.

• Comparative analysis focused on efficiency, cost, complexity, reliability, and suitability for different environments.

Objective: To demonstrate the effectiveness of IoT-based smart humidifiers, highlighting trade-offs between ultrasonic and mechanical methods for indoor comfort, automation, and energy efficiency.

Conclusion

This project successfully demonstrated the development, automation, and comparative analysis of two types of room humidifiers—an Ultrasonic Humidifier and a Mechanically Operated Humidifier, both controlled using a NodeMCU microcontroller and a DHT11 humidity sensor. The aim was to maintain optimal indoor humidity levels through smart automation, while evaluating the differences in performance, cost, and user experience between the two models.

References

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Copyright

Copyright © 2025 Laxmikant Mangate, Gaurav Khochare, Rudra Kochari, Siddhant Kokani, Ravina Kubade. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.