Ambienttemperature and humidity are important factors that affect the efficiency and effectivenessof daily life activities. This study was conducted to examine the behaviours,productivity and comfort of the students in our experimental group at the specifiedtemperature intervals.
Amicrocontroller-based embedded system was used for this purpose and this systemis designed to monitor the temperature and humidity values of the environment.The special Arduino microcontroller we use is enriched with sensors such asDHT11 and ESP8266, and has been turned into a suitable working mechanism forour goal.Afterthe technical installation and software operations have been completed and thedevice has become operational, the determined area and the experiment grouphave been tested and the results have been recorded.Firstand foremost, we have to thank our project supervisor, Mr. Gökhan Kirkil.Without his assistance and dedicated involvement in every step throughout theproject, this paper would have never been accomplished. Also, special thanks toMr. Orçun Kepez for his help and many precious ideas about our discussion.
Wefeel very lucky to had the opportunity to work with him. We also take this chanceto express gratitude to all of the Kadir Has University Engineering and NaturalScience Faculty members for their help and support in all four years.Firstof all, we want to mention some basic concepts. Heat is a form of energy measurable in terms of temperature bythermometers.
In a natural environment, human body can experience extreme heatswhich is in a range of arctic cold to tropical heat. And the temperature of theenvironment influences the body temperature. That makes the indoor temperature veryimportant.Indoor temperature is one of thefundamental characteristics of the indoor environment and ?t can be controlledwith the building and its HVAC system1.HVAC isthe system of heating, ventilating and air conditioning.Researcheshave lots of different ideas about the best indoor temperature, but they agreethat it should be in a 20 -25 ° C range. We call it the best condition becausethe indoor temperature influences lots of human reactions like, thermalcomfort, perceived air quality and performance at work.
In this study, wefocused on the effects of temperature on performance at our school. Latestresearches shows that extreme indoor environmental conditions can affect healthand productivity in a negative way1. So engineers aretrying to improve indoor environments and control their effects to increaseefficiency and productivity. We collect the existing information and tried toget new test information on how temperature affects productivity andefficiency. Because when we know more about these effects, they could beincluded into cost-benefit calculations for the building design and operation.
Temperature’seffect on productivity is an important topic for researchers. There are lots ofexample studies about it. In this paper, we will talk about G, NECA andT’s original research data about temperature and productivity relationship.’Grimm and Wagner (1974)and The National Electrical Contractors Association (NECA 1969, NECA 2004) conducted experiments to measureproductivity under different weather conditions. Thomas and Yiakoumis (1987) developeda regression model using temperature and humidity to predict PR.’2(Ibbs& Sun Analysis of the MCAA Factor Model for Measuring Loss ofProductivity.)*TheProductivity Ratio (PR) represents the ratio of actual productivity divided by”optimal” productivity.
Theplotted areas on the chart show areas where temperature and humidity affectproductivity.Forexample, in Thomas and Yiakoumis’ s study, you can see the data shows there isa 100% productivity in 50°F.Asit seen, every research has its own peak PR’s at different temperature ranges. Theresults of the experiment differ from the environment in terms of theexperiment was conducted, the equipment used, the target audience and theexperimental purpose. We have tried to reach our own values and interpret themusing our own measuring method.
Inthis thesis, we designed our microcontroller-based embedded system to monitorthe temperature and humidity values of our test environment. In addition tomonitoring temperature and humidity, we can learn the heat index too. Heat index is a combination of airtemperature and relative humidity3. It also called’humiture’. 4 2.2.1 Heath Index Heatindex is what the temperature feels like to the human body when relativehumidity is combined with the air temperature.
This has importantconsiderations for the human body’s comfort. Hereis the equation of heath index when t representing the current air temperatureand r representing the current relative humidityWedesigned the system using Arduino Nano Microcontroller. A Microcontroller (MCU) is basically a simple computer.5There is a difference in desktops and microcontrollers. Desktops can run lotsof programs because they have software support for different hardwarecomponents.
But microcontrollers specifically written to control one hardwarecomponent can run one program only run one program.5 Arduinowebserver monitoring system was programmed using the C programming language.7 The sensor data is readand processed by Arduino and it is displayed to the user through the Gobetwinointerface.Wecreate the embedded system in two parts. ystemdesign was the theoretical part.This part describes, the use of the Arduino microcontroller and how it isutilized in the embedded systems in practical part. We create the design andarchitecture model in this phase. This part alsoincludes literaturereview.
Practical part describes the temperature and humidity monitoring system. I this part we complete the wiring diagram, the source code and implementation and testing.o Arduino Nanoo DHT11 Temperature and Humidity Sensoro Breadboardo Power supplyo Connecting wiresWe get the measurements of the class via Arduino Nano Heat and Humidity Calculation Device which we build and encode.
We use Arduino Nano, DHT11 humidity and temperature sensor to build a small circuit for measurements and ESP8266 Wi-Fi module and Gobetwino for getting the data and save them in a txt format.Some details about the components which we use;Technically, Arduino is a programmable logic controller. Officially, it’s an open-source electronics prototyping platform. 6 Basically, Arduino boards are able to read inputs (ex. message, heath or light) and turn it into an output (ex. turning on led, activating a motor, display it in the screen).
You can tell your board what to do by sending a set of instructions to the microcontroller on the board. For example, you can obtain some test results using customized Arduino components for humidity and temperature measurements, as we did in this experiment. Inthis study we use Arduino Nano which is a common type of Arduino to use.
Themajor difference between the standard Arduino Uno and Arduino Nano is thenumber of Analog Pins and the USB Port We will discuss these components laterin detail. Thearduino advantages which described on the Arduino website are as follows13; Inexpensive – Arduino boards arerelatively inexpensive compared to other microcontroller platforms. Cross-platform – The ArduinoSoftware runs on many operating systems. It is not limited to Windows. Simple, clear programmingenvironment – The Arduino has an easy-to-use software and it is flexible todevelop. Open source and extensiblesoftware – The Arduino software is an open source tool so programmers can addextensions. Open source and extensiblehardware – Circuit designers can extend and improve it to make their ownversion of the module.TheArduino Software is a user friendly programming environment: It allows theprogrammer to create different programs and load them to Arduinomicrocontroller.
8The software also called ArduinoIDE (Integrated Development Environment). In DHTXX series there are two types ofhumidity sensors, DHT11 and DHT22. Both these sensors are Relative Humidity(RH) Sensor.
According to the Australian Bureau of Meteorology;Relative humidity (RH)The ratio of the actual amount of water vapour in theair to the amount it could hold.Absolute humidity (AH)The mass of water vapour in a unit volume of air. As a result, we can measure both the humidityand temperature. Inour project, we used DHT11 is a Humidity and Temperature Sensor, whichgenerates calibrated digital output. It can be interface with Arduino and itcan get instantaneous results. DHT11 provides high reliability and long termstability.
9TheDHT11 Humidity and Temperature Sensor consists of 3 main components. Aresistive type humidity sensor, an NTC (negative temperature coefficient)thermistor (to measure the temperature) and an 8-bit microcontroller.10 This microcontroller gets analog signals from thesensors and converts them to a single digital signal to send out. Youcan see the main specifications and differences between these two sensors intable 111. The more expensive option, DHT22 has some better specifications. DHT22has a wider temperature range.
When DHT11 can measure the temperature in 0 to50 degrees, DHT22 can measure it in -40 to 125 degrees. Also with +- 0.5 degreeaccuracy, DHT22 has more reliable results than DHT11. About humidity, DHT22 hasbetter humidity measuring range, from 0 to 100% with 2-5% accuracy, while theDHT11 humidity range is from 20 to 80% with 5% accuracy. There are some specifications which DHT11 isbetter than DHT22.
They are sampling rate and body size. Sampling rate forDHT11 is 1Hz or one reading every second, while the DHT22 sampling rate is0,5Hz or one reading every two seconds and also the DHT11 has smaller bodysize. Thesetwo sensors has the same operating voltages (from 3 to 5 volts) and same maxcurrents (2.
5mA) used when measuring.Gobetwinois kind of a “generic proxy” for Arduino.12It’s a program which is running on your computer and act on behalf of Arduinoand do some of the things that Arduino can’t do on its own.12Weuse Gobetwino program for display the data we get from the humidity andtemperature measurements with Arduino. And we save them as a text file onGobetwino.Beforebeginning to monitoring the class, certain requirements were set. The system isneeded to be easy to use and the user could remotely monitor environmentalchanges inside the class. Sensor data required to be collected and stored forshowing changes in the environment variables.
We had a fixed temperature to getreliable results. Themeasurements accomplished by the data communications between Arduino, DHT11Sensor Module, ESP8266 WIFI module and Gobetwino. Arduino’s Celsius scalethermometer and percentage scale humidity meter displays the ambienttemperature and humidity through Gobetwino display and also record it as a textfile. Wetake the measurements on 30.11.2017 and 07.
12.2017, 2 weeks consecutively, insmart class of Kadir Has University. We take two measurement tests by Arduinoeach day. One is before the class when the lecture didn’t start and one isafter the lecture, while the students write their reflection papers about thelecture and filling our survey questions. Wetry to figure out their comfort level in the temperature we fixed by HVACsystem and their motivation in this environment.
First week we fixed theclassroom temperature at 20.00 C ° and the second week we fixed it at 27.00 C°. There were 26 people in the test group and we neglected the genders andclothes while we commentate the results.Forthis experiment, we divided the class into eleven regions. We gave a number toeach region and recorded the results of each region separately.
We ensuredstudents sit in the same places in the two days of experiment. At the end ofthe class we asked the students to write a reflection paper about the lectureand to answer the survey questions which we gave them before the class. Weasked them for mark where they sit in class on the graph we gave them and markthe spot they want to sit if it is possible.
A systematic approach has been followed in measurement with the microcontrollerbased system. The results obtained fromthe measurement have shown that the system performance is reliable andaccurate. This project has been completed successfully. We get our data withArduino and transmit them wirelessly to a processing sketch, where they arevisualized for simple analysis. So our goal of integrating all of the underlying technologies has beenmet.