In this arduino based project, we are going to build a temperature-controlled fan using Arduino. With this circuit, we will be able to adjust the fan speed in our home or office according to the room temperature and also show the temperature and fan speed changes on a 16x2 LCD display. To do this we will be using an Arduino UNO Board, LCD, DHT11 sensor Module, and DC fan that is controlled by using PWM. Let's discuss more on this is done so that you can build one on your own. We have also built a project to perform Automatic AC temperature control, you can also check that out if you are intrested. 
This project consists of three sections. One senses the temperature by using humidity and temperature sensor namely DHT11. The second section reads the dht11 sensor module’s output and extracts temperature value into a suitable number in Celsius scale and control the fan speed by using PWM. And last part of system shows humidity and temperature on LCD and Fan driver.
Here in this project, we have used a sensor module namely DHT11 that already has discuss our previous project namely “Humidity and Temperature Measurement using Arduino”. Here we have only used this DHT sensor for sensing temperature, and then programmed our arduino according to the requirements.