The limitations of existing fans is that it is not energy efficient and has to be operated manually. It does not changes its speed according to the temperature at a given time of the environment. This project resolves the issue of energy efficiency by the use of temperature sensor thermistor and a comparator I.C. Also, the use of passive infrared  (PIR)sensor is also introduced in this project to aid the automatic start and stop of the system respectively. Due to the comparator I.C. used, there is an output signal that indicates when the fan or system turns on and off and also changes its speed from a high speed to a low speed vise versa. This system is very useful to both the disabled as well as old age people, because the overall system is controlled automatically. Conclusively, the system is energy efficient thereby reducing cost and save money.

CHAPTER ONE

1.0  INTRODUCTION

Automation is a technique, method, or system of operating or controlling a process by electronic devices with reducing human involvement to it’s minimum. The fundamental of building an automation system for an office or home is increasing day-by-day with numerous benefits. Automation makes not only an efficient, but also an economical use of the electricity.

This project presents an electric fan temperature control by using the current temperature in the room to change its speed, goes on when there is someone in the room and off when the person is out to save energy.  A fan is a machine used to create flow within a fluid, typically a gas such as air. The fan consists of a rotating arrangement of vanes or blades which act on the fluid. The rotating assembly of blades and hub is known as an impeller or rotor. Usually, it is contained within some form of housing or case. Most fans are powered by electric motors, but other sources of power may be used. Nowadays, living rooms are not well arranged with air ventilation. So fan is the main way of cooling down and is used in most of the houses but the electric fan doesn’t have any automatic or efficient feature. With the recent trend in technology, the home environment is made digital and automation friendly, so therefore equipment’s are made automated. The electric fan system has become a field to be researched to improve the user convenience by applying intelligent system such as micro controller. While the enhanced electric fan system is being designed, the consideration of the type of control system must be included in a modeling design. In particular the controller must be able to avoid the inefficiency of having the electric fan operate all the time. Several control options were considered at presence sensing circuit, which would turn the fan off when people are not in the room within 2 to 5 minutes with the electric fan and a temperature sensor input, which would change the electric fan operation to either high speed or low speed depending on room temperature. Based on the observation of using the present conventional fan, it is always working all the time without a systematic control. Therefore, the control of the fan is adjusted through a feedback control system to monitor and maintain a constant temperature based on the data input from the sensor.

A sensor is a type of transducer. In a broader sense, a transducer is mostly defined as any device that converts energy from one form to another. Besides that, the component that made up the temperature sensor is known as thermistor. Thermistor is a kind of temperature dependent resistor and its resistance varies depending on the temperature in its vicinity.

1.1  BACKGROUND OF THE STUDY  

Sometimes electric fan usage is wasting power because of human attitude. Human also mostly demands something that is easy to use without wasting energy. To minimize or reduce the power usage, this project developed an automatic fan system where it starts by noticing the presence of individual, speed is controlled by the room temperature and stop operation by the absence of individual in the room.

1.2. STATEMENT OF PROBLEM 

Most human feels inconvenient about changing the fan speed level manually when the room temperature changes or gets tired/lazy in turning the fan on and off. So, the automatic fan system that automatically changes the speed level according to temperature changes also start and stop due to the presence and absence of human respectively is recommended to be built for solving this problem. The advantages of such a system are less energy usage, and provides more convenient to the consumers.

The aim of this project is to design and construct a smart fan that is energy efficient in our homes, schools, hospitals and offices.

1.3. OBJECTIVES OF THE STUDY

The objectives of this project are to:

  1. Enable the electric fan to start and stop automatically.
  2. Enable the electric fan to automatically change the speed level according to temperature changes using a temperature sensor or thermistor.
  3. To analyses the performance of the controller.

1.4. SIGNIFICANCE OF THE STUDY

The significance of this project is to avoid the waste of energy by making the system energy efficient in our homes, offices and hospitals. Thereby reducing cost and save money from our power electrical bills.

1.5. SCOPE OF THE STUDY

Below are the scopes of the project:

1. The comparator I.C used in the design of the system

2. Inside the room temperature is used in the controller design.

3. The analysis controller performance in terms of automatic temperature control based on the speed of the fan system.