The main objective to research this project for the low cost, energy saving, automatic operation is done without the help of human being, this system is equipped with Zigbee (Zigbee is a communication protocol that uses Small, low-power digital radio signals) it is used For communication between IR sensor and microcontroller, In this system we have a corporate unit with both facilities of HVAC and Split units, Thus the system can also be used Fire safety device. When you decide to cool your entire home, split system air conditioners cooling system are the most common choice.

1. ISSN: XXXX-XXXX Volume X, Issue X, Month Year 1
Development of Embedded System for Saving Energy
in Air Conditioner
Sudha.S
Dept of Computer Science and Engineering
BTL Institute of Technology
Bangalore, India
ssudha1345@gmail.com
Ashritha.V
Dept of Computer Science and Engineering
BTL Institute of Technology
Bangalore, India
ashritha.so@gmail.com
Venugopal.R
Dept of Computer Science and Engineering
BTL Institute of Technology
Bangalore, India
venu14vgr@gmail.com
Karunashree.R
Dept of Computer Science and Engineering
BTL Institute of Technology
Bangalore, India
karunar0293@gmail.com
Abstract
The main objective to research this project for the low
cost, energy saving, automatic operation is done without the
help of human being, this system is equipped with Zigbee
(Zigbee is a communication protocol that uses Small, low-
power digital radio signals) it is used For communication
between IR sensor and microcontroller, In this system we
have a corporate unit with both facilities of HVAC and Split
units, Thus the system can also be used Fire safety device.
When you decide to cool your entire home, split system air
conditioners cooling system are the most common choice.
Keywords
Temperature sensors DS1620, Microcontroller 8051 and
IR sensor TSOP1938.
Introduction
These systems uses an Embedded system which is incor-
porated with 8051 micro controller which is an 8 bit control-
ler (Access 8 bit instruction at a time).faced with IR sensors
and temperature sensing IC as inputs. The IR sensors counts
the number of people entering and leaving the system and
updates the logic in the micro controller registers and sends
appropriate signals to the AC controllers via relays or
switching circuits which in turn stops/resumes the cooling.
In case the number of employees working in the building
is less than 35% then the HVAC is turned off and Split AC’s
are turned on. This IC also sends signals to the micro con-
troller incase of high temperatures reached and micro con-
troller can send alarm signal.
In this system, to improve the Development of embedded
system for Saving Energy in Air Conditioner it tracks the
number of persons entering to the corporate bay and switch-
es/regulates HVAC or Split units.
AC in Corporate
HVAC – Heating Ventilation and Air cooling plays a vital
role in Corporate.
Brief on AC and Electrical Energy: The thumb rule of plan-
ning a AC system is for every 100 -110 sft we require 1 Tr
of AC in corporate world wherein TR is defined a Tons of
refrigeration. (1 TR: 1 tone of refrigeration is the rate of heat
removal required to freeze a metric ton (1000 kg) of water at
0°C in 24 hours).
To achieve this we require 3.517kW approx. If a corporate
place of 1, 00,000sft requires a AC unit. Then we require at
least 1000 TR of Chiller plant.

2. International Journal of Innovatory Research in Science and Management – IJIRSM www.ijirusa.webs.com
ISSN: XXXX-XXXX Volume X, Issue X, Month Year 2
So 1000Tr x 3.14Kw = 3140kW is required as a pre demand
which is very huge. Efficiently using AC can help us in sav-
ing energy by using SOP for efficient usage.
Microcontroller 8051
Fig1 8051 Microcontroller
128 byte RAM
4kb ROM
2timer
4ports
Port0->data address
Port1, port3->interfacing
Port2-> low port of the address
Port3->Multifunction
To control the efficiency of AC system using microcontrol-
ler it is loaded with a hex code which is converted from a
Embedded C program.
Interrupts: As the name suggests, Interrupt is a subroutine
call that interrupts microcontroller during the process or ex-
ecution of any program which is important at that time
.
CPU: It monitors and controls all operations that are per-
formed in the microcontroller. It reads the program that is in
the ROM memory and executes them and does the expected
task.
Memory: Microcontroller requires two kinds of memory
such as RAM and ROM.ROM for the program to be saved
and read by the microcontroller RAM for the temporary
storage of data.
BUS: It is a collection of wires which works as a communi-
cation channel or medium for the transfer of Data.
The two types of buses are:
Address bus-It has 16 bit address bus used to address
memory locations that transfers the address from CPU to
memory.
Data bus-It has 8 bit data bus that is used to carry data.
Oscillator:8051 has an on-chip oscillator which works as a
clock source for CPU.As the output pulses of, oscillator are
stable therefore it enables synchronized work of all parts of
microcontroller.
Input/output Port: Microcontroller is used in the embedded
systems to control the operations of machines therefore to
connect it to other machines or devices we require I/O ports.
Timers/Counters: 8051 has two 16-bit timers and counters.
The counters are divided into 8-bit registers. The timers are
used for measurement of intervals, to determine pulse width.
Proposed System
In this proposed system, to improve the Development of
embedded system for Saving Energy in Air Conditioner it
tracks the number of persons entering to the corporate bay
and switches/regulates HVAC or Split units. Also it regu-
lates the temperature as per real time and also gives alarm
incase more temperature is reached. The System is also
equipped with Zig-bee to transmit data of people from dif-
ferent places in the Facility. Our project assumes having a
corporate unit with both facilities of HVAC and Split units.
In case the number of employees working in the building is
less than 35% then the HVAC is turned off and Split AC’s
are turned On, This IC also sends signals to the microcon-
troller in case of high temperatures reached and microcon-
troller can send alarm signal. Thus the system can also be
used Fire safety device. Whenever it increase the high tem-
perature the microcontroller signals to the buzzer this buzzer
produces the beep sound to alert the people during fire acci-
dent in the same time fire safety device is activated.
Advantages of Air Conditioner Using
Zigbee
• Energy Saving to a great Extend.
• Supports Green Energy.
• We can also have an idea of how many people are
there in the building therefore we can plan evacua-
tion in a efficient in case of any emergency scenari-
os like Fire, Earth quake.
• The micro controller is interfaced with IR sensors
and temperature sensing IC as inputs.

3. International Journal of Innovatory Research in Science and Management – IJIRSM www.ijirusa.webs.com
ISSN: XXXX-XXXX Volume X, Issue X, Month Year 3
• The IR sensors counts the number of people enter-
ing and leaving the system and updates the logic in
the micro controller registers and sends appropriate
signals to the AC controllers via relays or switching
circuits which in turn stops/resumes the cooling.
• Even as the temperature sensor IC monitors the
room temperature constantly and sends signals to
the micro controller to maintain the room tempera-
ture.
Block Diagram
Fig2 Interfacing via microcontroller
Working principle of air conditioner
In the fig2, whenever a person crosses the IR signal in the
fig2, the IR signal is interrupted. The microcontroller incre-
ments the count and displays on to the LCD. Accordingly
the temperature sensor is activated, for specified temperature
increase it gives signal to the microcontroller to turn ON the
Relay units and the respective ACs will be started. As shown
in the fig2.This process goes on until the number of mem-
bers exceeds 10 (or as per requirement).When members ex-
ceed 10, mini-fans are activated by microcontroller, accord-
ing to the temperature readings. If members are below 10,
mini fans are deactivated. If members entering more than
100 in the bay then HVAC is activated automatically
(HVAC is the technology of indoor and vehicular environ-
mental comfort). HVAC is important in the design of medi-
um to large industrial and office buildings such as skyscrap-
ers and in marine environments such as aquariums, where
safe and healthy building conditions are regulated with re-
spect to temperature and humidity, using fresh air from out-
doors.
Flow Chart
Fig3 algorithm for temp check
In the fig3 it checks the temperature. If the temperature is
lesser than 25 degree celsius then it turns off the HVAC and
if the temperature is greater than 25 degree celsius then it
turns on the HVAC.
Fig4 algorithm for switching HVAC to split
In fig4 First it will check the number of members entering
into the room, if number of people is less than 35% in the
room HVAC will be turned OFF and split AC will be turned
ON, otherwise if number of people more than 35% in the
room HVAC will be turned ON and split AC will be turned
OFF.

4. International Journal of Innovatory Research in Science and Management – IJIRSM www.ijirusa.webs.com
ISSN: XXXX-XXXX Volume X, Issue X, Month Year 4
Conclusion
The method of automatic people counting used in air-
conditioning energy-saving is effective and has high recog-
nition rate in indoor environment, counting the number of
people through the IR sensors and displaying it in LCD has
lower cost. Current air-conditioning energy-saving hasn’t
been found to recognize technology such as people counting
method control system to realize energy-saving.
References
[1] T.Zhao, R.Nevatia, B, Wu, “Segmentation and tracking
of multiple humans in crowded environment,” IEEE Trans-
actions on Pattern Analysis and Machine Intelligence, vol
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[2] T.Zhao, R.Nevatia, “Tracking multiple humans in com-
plex situation,”IEEE Transactions on Pattern Analysis and
Machine Intelligence, vol .26, no 9, 2004, pp.1208-1221.
[3] Ya-li Hou, Grantham K.H.Pang, “Automated people
counting at a mass site,” IEEE International conference on
Automation and Logistics, 2008.
[4] pp.464-469] Massimiliano Bozzoli, Luigi Cinque, Enver
Sangineto, “A
Statistical method for people counting in crowded environ-
ments,”14th
International conference on Image Analysis and
Processing (ICIAP 2007),2007,pp.506-511.
[5] Wei Di; Rongben Wang, “Driver Eyes Identification
Based on Infrared Illuminator, ”International conference on
Computational Intelligence and Software engineering( CISE
),2009,pp. 1-4.
[6] Zhang Da-kun, “An Extended Opening Operation and Its
Application in Image Processing,” International Conference
on Multimedia andInformation Technology, 2008,pp. 377-
380
Biographies
Ms.Sudha.S.
B.E (Computer Science Engineering)
from BTL Institute of Technology, Ban-
galore, and her area of research is em-
bedded system.
Mr. Venugopal.R
B.E (Computer Science Engineering)
from BTL Institute of Technology, Ban-
galore, and his area of research is Em-
bedded system.
Ms.Ashritha.V.
B.E (Computer Science Engineering)
from BTL Institute of Technology,
Bangalore, and her area of research is
Embedded system.
Ms.Karunashree.R.
B.E (Computer Science Engineering)
from BTL Institute of Technology,
Bangalore,and her area of research is
Embedded system.