Abstract
This paper presents the design of an energy-efficient fan control system using Arduino technology, specifically tailored for smart home applications in Nigerian households. Leveraging the Arduino Uno microcontroller, temperature sensor, Passive Infrared (PIR) sensor, and ultrasonic sensor, the system dynamically regulates fan operation based on room temperature and occupancy. The temperature sensor monitors ambient conditions, while the PIR sensor detects human presence, ensuring the fan only operates when necessary to conserve energy. Additionally, an ultrasonic sensor identifies obstructions or movement to enhance system responsiveness and safety. This smart fan controller aims to reduce power consumption in Nigerian homes by minimizing waste and optimizing energy use, making it particularly valuable in regions where electricity access is limited or intermittent. The proposed solution demonstrates a cost-effective, adaptable approach to sustainable energy management, offering significant potential for application in developing regions.
Keywords: Energy efficiency, Smart home, Arduino technology, Microcontroller, Temperature sensor
Author: Okoh Vivian. O.
Supervising Lecturer: Dr. C. U. Eya
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Well done Author
What are the modalities put in place for the efficient use of this fan?
Full of wisdom and perfect in beauty
Thanks so much
Thanks so much
For the efficient use of this Arduino-based fan controller in Nigerian households, the fan speed is regulated based on real-time room temperature using a temperature sensor. When the temperature rises above a set threshold, the fan speed increases; when it drops, the speed decreases or the fan turns off, preventing unnecessary energy consumption. Additionally, passive infrared and ultrasonic sensors were integrated to detect human presence and turn the fan on or off accordingly. This prevents energy wastage when the room is unoccupied.
Nice one Author
How does this fan controller address the issue of voltage fluctuations and power outages common in Nigerian households?
Thanks so much dear
The variable-speed voltage controller adjusts the fan’s speed based on the available voltage. During periods of low voltage, it ensures the fan continues to operate at a reduced but stable speed rather than shutting off completely. In the case of high voltage, it regulates the power supplied to the fan motor, helping to prevent overloading and potential damage.
While this paper primarily focuses on energy saving and improving user comfort, rather than addressing power outages, the system can still be beneficial in such scenarios. When connected to an inverter or solar system, the variable-speed controller optimizes power consumption by running the fan at lower speeds when backup power is limited. This helps extend battery life and allows for longer fan operation during outages.
By dynamically adjusting voltage and speed, this fan controller not only enhances energy efficiency and user convenience but also contributes to the longevity and reliable performance of the fan, even in the face of Nigeria’s frequent voltage fluctuations and power challenges.
Nice work 👍🏽
This is a good development. I have always had the issue of sleeping under a fan and having to wake up and manually regulate it so I don’t get cold. Thank you for bringing up this solution.
I would like to ask if it is going to run only automatically or can it be both automatic and manual, for users that wants to get cold?
You are very much welcome
Yes, users with preferences can easily override the automatic function and switch between manual and automatic operation as needed.
Nice work
Welldone 👏. A very wonderful work
Thanks so much
I accidentally disliked this article, but I actually think it’s a well researched and valuable piece of work 👍
Great 👍
Weldone
Thank you
Very insightful. Thanks for sharing your knowledge.
Thanks dear
This is nice. The PIR which works on the infrared sensor principle, can it identify the difference between an animal and humans because it may cause problems for people who have pets. If the pet continues running around the room or moving in and out of the room, the fan keeps working which may lead to overheating of the system due to on and off
Thanks dear
The dual-sensor approach (PIR + ultrasonic) helps reduce false activations from pets by setting a height threshold, filtering out motion below a certain level. This ensures that small animals do not trigger the fan unnecessarily, reducing energy waste and preventing excessive on/off cycles
Nice work
In a situation where an individual experience a rise in body temperature due to illness and the ambient temperature is cold but the person needs the fan to rotate fast to alleviate his or her discomfort will the temperature sensor also detect the human body temperature?
Thanks dear
For now, the system prioritizes room temperature and motion detection to optimize energy efficiency while allowing for future user-based customization.
The temperature sensor (DHT11) measures ambient temperature, not body temperature, so if the room is cold, the fan would normally run at a lower speed. This means that if an individual has a high body temperature due to illness, the fan may not respond as needed.
A potential improvement to address this is incorporating a manual override feature, allowing users to adjust the fan speed manually when necessary. Additionally, integrating a body temperature sensor or wearable device in future versions could enable automatic adjustments based on individual comfort needs.
Nice work indeed! 👍
Concerning the PIR sensor that detects human presence, assuming this fan is installed in a room with a single occupant (one person) and another room with more than ten occupants; will the fan still function at the same speed in both rooms considering the number of occupants?
Thanks dear
The PIR sensor in my fan controller detects the presence of people but does not count the number of occupants. This means that whether there is one person or ten people, the fan activation is based on motion detection, not crowd size.
However, the temperature sensor (DHT11) helps adjust the fan speed based on ambient temperature. In a room with more occupants, body heat may naturally raise the temperature, causing the fan to run at a higher speed. If the temperature remains low despite multiple occupants, the fan speed will not change significantly.
A possible future enhancement could involve integrating CO₂ sensors or thermal imaging to detect crowd density more accurately and adjust fan speed accordingly.
Well done Vivian!! Your paper is intriguing and all more exciting as it models a fan as a unity feedback closed-loop control system and all more profound is the featuring of the root-locus criterion. However, the model being utilized does not seem to explicitly distinguish the poles in the system from the zeros. What are your system poles? In addition, your paper does not seem to address the issue of system stability or steady-state error which are fundamental to system makeup, for what valid range of inputs is your system matrix stable and your output valid and how do you think the system’s steady-state error can be reduced? Thanks and well done!!
Thank you for your insightful feedback and appreciation of my work! While my paper models the fan as a unity feedback closed-loop control system, it does not use the root locus criterion for stability analysis. Instead, I focus on PID control measures to enhance system stability and performance.
Regarding the system poles and zeros, the poles are derived from the denominator of the closed-loop transfer function, determining stability, while the zeros come from the numerator and influence transient response. I acknowledge that explicitly distinguishing them can improve clarity and will refine this aspect further.
For system stability, I suggested methods like Routh-Hurwitz criterion which can be used to determine a valid input range. Since my system relies on PID control, proper tuning ensures the poles remain in the left-half of the s-plane for stability.
On steady-state error reduction, the integral component in PID control helps minimize error, driving it to zero for step inputs, while proportional and derivative terms further refine the response.
However, considering the scope of my paper—’Energy Efficiency In Smart Home Systems: Design Of An Arduino-Based Fan Controller For Nigerian Households’—the primary focus was on energy efficiency and intelligent control rather than an in-depth mathematical stability analysis. While these aspects are essential in control system design, the paper prioritizes practical implementation and performance optimization in real-world conditions.
I sincerely appreciate your valuable feedback and will consider refining certain explanations to enhance clarity. Thank you once again!
Very good write up Vivian
Questions:
1. How does the temperature sensor (DHT11) measure ambient temperature, and what signal processing steps are involved?
2. Is it possible I use Routh-Hurwitz criterion to analyze the stability of the system. If Yes. How?? If No explain.
3. How does system gain (K) influence the speed control of the fan?
1. The DHT11 sensor measures ambient temperature using a thermistor (a temperature-sensitive resistor). The sensor converts temperature changes into an electrical signal, which is processed by an internal 8-bit microcontroller. The microcontroller digitizes the signal and transmits temperature data via a single-wire communication protocol to the Arduino. The Arduino then processes this data to control the fan speed accordingly
2.
Yes
The Routh-hurwitz is primarily used for analyzing the stability of continuous-time linear control systems by checking if all roots of the characteristic equation lie in the left -half of the s-plane.
For my fan controller, which I modelled mathematically as a transfer function in the Laplace domain. I can apply Routh-hurwitz to determine whether the system remains stable under different gain (K) values.
Firstly, I will obtain the characteristic equation. And in the paper, I already gave the characteristic equation of a closed loop system. Now, I can model the system as a second or higher order system, and the characteristic equation will be a polynomial.
Secondly, I will construct the Routh Array which I will build using the coefficients of the characteristic equation.
Thirdly, I will check stability conditions. The system is stable if all the first column elements of the Routh Array are positive and do not change sign.
If any coefficient is negative or changes sign, the system has unstable poles (right -half plane) indicating instability.
If any row has a zero, special methods like the auxiliary equations are used.
If all coefficients are positive with no sign changes, the system is stable (poles in the left -half plane).
Lastly, I will apply to my fan controller. The Routh-hurwitz, helps determine the range of K that keeps all first column elements positive, ensuring stability.
In summary, applying Routh-hurwitz criterion analyzes how different values of K impact stability, which helps in designing a fan controller that is responsive yet stable.
In a closed-loop fan speed control system, the gain (K) determines how aggressively the system responds to changes in temperature or occupancy.
Low K: The fan responds slowly, causing sluggish speed adjustments.
High K: The fan reacts faster, but excessive gain can cause overshoot or oscillations, leading to instability.
Tuning K appropriately ensures smooth operation—balancing fast response and system stability to optimize energy efficiency and comfort.
Thanks so much for your feedback
This is great. Weldon Vivian
Thanks dear
Good Work Vivian,
How does your fan controller differentiate itself from other energy-efficient fan systems currently available in the Nigerian market?
And, what can give it the breakthrough in the Nigerian market?.
My fan controller stands out from other energy-efficient fan systems in Nigeria by integrating multiple smart sensors—PIR, ultrasonic, and temperature sensors—to optimize power consumption and user comfort. Unlike conventional systems that rely solely on temperature-based control, my design:
Detects human presence and movement using PIR and ultrasonic sensors, ensuring the fan operates only when needed, reducing unnecessary power consumption.
Adjusts fan speed dynamically based on room temperature, providing enhanced comfort while minimizing energy use.
Features a dual-sensor approach (PIR & ultrasonic) to improve accuracy in detecting occupancy, eliminating false triggers from static individuals that PIR sensors alone might miss.
Uses Arduino for customizable control and can be further upgraded to support IoT for remote monitoring and automation.
This combination makes it more intelligent, efficient, and adaptable compared to existing market alternatives.
For the fan controller to break into the Nigerian market, it must be affordable and adapted to local needs, ensuring cost-effectiveness. Its energy efficiency and solar compatibility make it ideal for areas with unstable power supply. Easy installation and low maintenance enhance adoption, while market education and strategic partnerships with homebuilders and institutions will drive widespread acceptance.
This is a good development. Ride on my dear.
Hello Vivian! You and your supervising lecturer, Dr. C. U. Eya, have done a really good job here. I must commend how you have made your work easy and comprehensible for your readers.
Question: Is there a provision for “settings” where the user can customize the operating temperatures of the automatic fan to their preference? For example, a user may wish to maintain their home temperature at above 20 degrees Celsius.
Furthermore, you said in your flowchart steps no. 3, that the system is only triggered by the presence of an occupant after which other processes follow, and according to your response to Nelson, the dual sensor system checks false activation by height threshold.
Now secondly, what is the means for regulation if there are sizable pets in the house and the occupant has a little stature?
Thank you so much.
This is a well-designed and innovative approach to energy-efficient home automation. Your use of multiple sensors enhances both functionality and efficiency, making it highly relevant for Nigerian households. Well done, Okoh Vivian O.!
A quick question: How does the system handle brief absences, such as when someone leaves the room for a few minutes—does the fan turn off immediately, or is there a delay to prevent frequent switching?