This document provides information about window air conditioners, including their parts, working principles, advantages, and classification of air conditioners more broadly. It describes the key components of a window AC unit, including the refrigeration system (compressor, condenser, expansion valve, evaporator), air circulation system (blower, fans), and control system. It explains the two air cycles in a window AC: the room air cycle where hot room air is filtered, cooled by the evaporator, and blown into the room, and the hot air cycle where heat is transferred from the condenser to the outside air. Window ACs are classified as unitary or packed systems that are convenient and inexpensive but use more energy than other options.

2. 3
1. What is meant by“Air
conditioning”?
2. Human Comfort
3. Why do we needA.C.?
4. Advantages and
Disadvantage ofA.C.
5. Ideal roomtemperature
6. some terminology-
 Dry-bulb temperature
 Wet-bulb temperature:
 Dew point
 Latent heat
 Absolute humidity
 Relative humidity
 Specific humidity
 Sensible heat
 Evaporating Cooling
 Condensation
 Enthalpy
 Entropy
7.Classfication of air conditioners
8.Windows AC- advantages
Parts of the Window Air Conditioners
Working
the refrigeration system,
air circulation system-room air cycle and
the hot aircycle.
 ventilation system,
 control system,
 electrical protection
system.
9.Split or Ductless AC-
advantages, parts indoor and
outdoor, types-
 Wall mounted
 Floor mounted/TowerAC
 Ceiling mounted/CassetteAC
 Multi Split ACs
10.Central Air
ConditioningSystem
Advantages and
disadvantages
11. Key differences
between "Window",
"Split" and a "cassette"
air conditioners.
12.Cooling capacity
13.Energy Efficiency
14.Energy Consumption
15.Energy Efficiency Ratio
16.Energy Saving Methods

3.  Air conditioning (often referred to as A/C or AC )
is the process of altering theproperties
of air (primarily temperature and humidity) to more
comfortable conditions, typically with the aim of
distributing the conditioned air to an occupied space
to improve thermal comfort and indoor air quality .
 Air conditioningis defined as a process which cools (or
heat) , clean, circulates, freshen air, and controls its
moisture content simultaneously.
 Most of the air conditioning, particularly in India and
such other countries, is about cooling : i.e. removal of
heat from an enclosedspace.
 In the most general sense, air conditioning can refer to
any form of technology that modifies the condition of
air (heating, cooling, (de-)humidification, cleaning,
ventilation, or air movement).
3

4. THE FOUR ATMOSPHERIC CONDITION WHICH AFFECT HUMAN
COMFORTS ARE-
Temperature, Humidity, Air purity
&
Air
movemen
ts.
 An air conditioner controls the above factors for us to achieve human comfort.
 Most people (90%) are comfortable when the air temperature is between 18-22°C and the % humidity is
between 40-65%.
4

5.  IN A WELL CLIMATICALLY DESIGNED BUILDING HUMAN COMFORT
FACTORS ARE CONTROLLED NATURALLY, THAT IS THE BEST SOLUTION.
5
 In big building/complexes it is not possible to design entire building
comfortably bynatural energy sources like sun, wind, orientation etc.
 In such cases we have to take the help of mechanical mean for obtaining
comfortable
conditions inside the building.
 The science & practice of creating a controlled climate in indoor space is
called Air-
conditioning.
 Outside air is quite likely to be at a different condition from the required
comfort zone condition. In order to bring its condition to within the
comfort zone we may need to do one or more of the following:-heat it;

6. ADVANTAGES:
6
 Increased comfortlevel.
 In extreme heat, air-conditioning can
be a life saver.
 Most air conditioners also reduce the
humidity level, which helps both
comfort, and reduces moldgrowth.
 Less noise as the windows will be
closed
 Prevents the dust entering the room
as the windows will be closed
 Gives constanttemperature
 Attractive design
 Simple control
 Easy maintenance
 Easy installation
Disadvantage
 Most air conditioners use a substantial
amount of energy,
 High cost money
 Contributing to pollution from power plants.
 Older models contain chemicals that can
damage the environment if theyescape.
 Encourageslaziness,
 Habitant spending time indoors instead of out
 Habitants have less contact withnature.
 Too cool temperatureswill lead to improper
blood
circulation
 Effects the environment by releasingthe cfc's.

7. s. n Type of Space Summer(°C) Winter(°C)
1. Residences, apartments, hotel and motel guest rooms , offices,
conferencerooms, classrooms, courtrooms, and hospital patient
23–26 20–22
2. Theaters , auditoriums, churches, chapels, synagogues, assembly halls, lobbies,
and lounge
24–27 21–22
3. Restaurants, cafeterias, and bars 22–26 20–21
4. Retail shops and supermarkets 23–27 18–20
5. Medical intensive care rooms 22–26 22–26
6. Factories and industrial shops 27–29 18–20
7. Machinery spaces, foundries, boiler shops, and garages - 10–16
8. Kitchens and laundries 24–27 18–20
7

8. DRY-BULB TEMPERATURE:
8
 It is the temperature of air measuredby a
thermometer freely exposed to the air but
shielded from radiation and moisture.
 Dry bulb temperature is the temperature that is
usually thought of as air temperature, and it is
the true thermodynamic temperature.
 It is the temperature measuredby a regular
thermometer exposed to theairstream.
 It is the temperature shown by a dry sensing
element
such as mercuryin a glass tube thermometer.
 This is actual temperature.
 When people refer to the temperature of the air,
they
are normally referring to its dry bulb temperature.
 The Dry Bulb Temperature refers basically to the
ambient air temperature. It is called "Dry Bulb"
because the air temperature is indicated by a
Wet-bulb temperature
 It is a type of temperature
measurement that reflects the
physical properties of a system with
a mixture of a gas and a vapour ,
usually air and water vapour .
 Wet bulb temperature is the lowest
temperature that can be reached by
the evaporation ofwater only.
 This is the temperature indicated by
a moistened thermometerbulb
exposed to the air flow.
 The wet bulb temperature is always
lower than the dry bulb temperature
but will be identical with 100%
relative humidity.
 This is the temperaturewe feel.

9. DEW POINT:
 The dew point is a saturation temperature.
 The temperature at which the air is saturated
(100% RH) and further cooling manifests in
condensation fromwater in the air.
 The dew point is the temperature at which
water vapour starts to condense out of the air
(the temperature at which air becomes
completely saturated).
 Above this temperature the moisture will stay in
the air.
 If the dew-point temperature is close to the dry
air temperature - the relative humidity is high
 If the dew point is well below the dry air
temperature - the relative humidity is low
 All pure substances in nature are
able to change their state.
 Solids can become liquids (ice to water)
and liquids can become gases (water
to vapor) but changes such as these
require the addition or removal of heat.
 The heat that causes these changes is
called latent heat.
 Heat energy added or removed as a
substance
changes state, whilst temperature
remains
constant,
 E.G. Water changing to steam at 100ƒc
and atmospheric pressure (W).
10
LATENT HEAT :

10. Absolute humidity:
Absolute humidity is the total amount of
water vapour present in a given volume of
air. It does not take temperature into
consideration.
Relative humidity:
 Relative humidity (RH) is the ratio of
water contained in air at a given dry
bulb temperature, as a percentage of
the maximum amount of water that
could be held in air at that temperature.
 Thus the relative humidity of air is a
function of both water content and
temperature.
SPECIFIC HUMIDITY:
 specific humidity is the mass of water
vapour present in a unit mass of air.
 Where temperatures are high and
rainfall is excessive, the specific
humidity of the air reaches high
proportions.
 This is also called “moisture content” .
Sensible heat gain:
 when an object is heated, its temperature
rises as heat is added. The increase in
heat is called sensible heat.
 Similarly, when heat is removed from an
object and its temperature falls, the heat
removed is also called sensibleheat.
 Heat that causes a change in temperature
in an
object is called sensible heat.

11. EVAPORATIVE
COOLING :
Evaporative cooling produces effective
cooling by combining a natural process -
water evaporation - with a simple, reliable
air-moving system.
Condensation :
Condensation is the change of the
physical state of matter from gaseous
phase into liquid phase, and is the
reverse of evaporation.
Enthalpy:
Total heat energy, i.E. Sensible heat + latent
heat. Specific enthalpy (kj/kg dry air).
Entropy:
Measure of total heat energy in a
refrigerant for every degree of
temperature (kj/kgƒc)

12. Classification based on major function:-
(a) Comfort A.C.: Creating atmospheric conditions
conductive to human health, comfort & efficiency. A.C. in
home, offices, stores,
restaurants, theatres, hospitals etc. are of these types.
CLASSIFICATION BASED ON SEASON
OF THE YEAR:
12
(b) Industrial A.C.: The purpose of these system is to
control atmospheric conditions primarily for proper conduct
of research & manufacturing e.g. electronics & computer
industries, paper mills, textile mills, candy factories, photo
processing etc.
a)Winter A.C.: system: These systems,
when properly designed & installed
maintain indoor atmospheric conditions for
winter comfortable, namely temperature,
humidity. Air purity &air
movements, when outside temperature is
very cold.
b) Summer A.C.: Maintains indoor
condition comfortable when outside
atmospheric conditions are not comfortable,
but it is very hot &dry.
c) All year round A.C.: Maintains
indoor temperature comfortable throughout
the year, while outside temperature may be
very cold orhot.
Classification based on equipments
arranged:
a) Unitary or “packed” A.C.
b) Spit A.C.
c)Central A.C.
d) Combination of above.

13. 14
Classification basedon installation
position WindowsAC
Split or Ductless
AC Centralised
AC
WINDOWS AC
• These types of AC are designed
to be fitted in window sills.
• A single unit of Window Air
Conditioner houses all the
necessarycomponents,
namely the compressor, condenser,
expansion valve or coil, evaporator
and cooling coil enclosed in a
single box.
• Since a window AC is a single unit,
it takes less effort to install as well
as for
maintenance.
• This is the most commonly
used air conditioner for single
rooms.
Advantages
•Single unit air conditioner
•Less effort needed for
installation
•Costs lesser in comparison to
other varieties

14. The whole assembly of
the window air
conditioner can be
divided into two
compartments:
 the room side, which
is also the cooling
side and
 the outdoor side from
where the heat
absorbed by the room
air is liberated to the
atmosphere.
The room side and
outdoor side are
separated from each
other by an insulated
partition enclosed inside
the window air
 In the front of the
window air
conditioner on the
room side there is
beautifully decorated
front panel on which
the supply and
return air grills are
fitted (the whole
front panel itself is
commonly called as
front grill).
 The louvers fitted in
the supply air grills
are adjustable so as
to supply the air in
desired direction.
 There is also one
opening in the grill
that allows access to
the control panel or
operating panel in
front of the window
PARTS OF THE
WINDOW
AIR
CONDITIONERS

15. 16
The various parts of the
window air conditioner
can be divided into
following categories:
 the
refrigeration
system,
 air circulation
system,
 ventilation system,
 control system,
 electrical
protection
system.

16. THE REFRIGERATION SYSTEM OF THE WINDOW AIR CONDITIONER COMPRISES OF ALL THE
IMPORTANT PARTS OF THE REFRIGERATION CYCLE. THESE INCLUDE
16
 the compressor,
 condenser,
 expansion valve and
 the evaporator.
 The refrigerant used in most of the window air conditioners is R22.
 The compressor used in the window air conditioners is hermetically sealed type, which is portable one. This
compressor has long life and it carries long warranty periods. The condenser is made up of copper tubing and
it is cooled by the atmospheric air. The condenser is covered with the fins to enable faster heat transfer rate
from it.
 The capillary tubing made up of various rounds of the copper coil is used as the expansion valve in the
window air conditioners. Just before the capillary there is drier filter that filters the refrigerant and also
removes the moisture particles, if present in the refrigerant.
 Like condenser, the evaporator is also made up of copper tubing of number of turns and is covered with the
fins.
 The evaporator is also called as the cooling coil since the rooms air passes over it and gets cooled. Just
in front of the evaporator there is air filter fitted in the front panel or frontgrill.
 As the room air is absorbed, it is first passed over the filter so that it gets filtered. The filtered air is then
blown over the cooling coil and the chilled air is passed into the room.

17. 17

18. 19
THE AIR CIRCULATION SYSTEM OF THE WINDOW AIR
CONDITIONER COMPRISES OF THE FOLLOWING PARTS.
1) Blower: This is the small blower that is fitted
behind the evaporator or cooling coil inside the
assembly of the
window air conditioner system. The blower sucks
the air from the room which first passes over the air
filterand
gets filtered. The air then passes over the cooling
coil and gets chilled. The blower then blows this
filtered and chilled
air, which passes through the supply air
compartment inside the window air conditioner
assembly. This air is then
delivered into the room from the supply air grill of
the front panel.
2)Propeller fan or the condenser fan: The
condenser fan is the forced draft type of propeller fan that
sucks the atmospheric air and blows it over the
condenser. The hot refrigerant inside the condenser gives
up the heat to the atmospheric air and its temperature
reduces.
3) Fan motor: The motor inside the window air
conditioner
assembly is located between the condenser and the
evaporator coil. It has double shaft on one side of which
the blower is fitted and on the other side the condenser
highly
compact.

19. The working of window air
conditioner can be
explained by separately
considering the two
cycles of air:
 room air cycle and
 the hot air cycle.
ROOM AIR CYCLE
19
 The air moving inside the room and in the front part of the air conditioner
where the cooling coil is located is considered to be the room air. When the
window AC is started the blower starts immediately and after a few seconds
the compressor also starts. The evaporator coil or the cooling gets cooled as
soon as the compressor is started.
 The blower behind the cooling coil starts sucking the room air, which is at high
temperature and also carries the dirt and dust particles. On its path towards the
blower, the room air first passes through the filter where the dirt and dust
particles from it get removed.
 The air then passes over the cooling coil where two processes occur. Firstly,
Dueto this the temperature of the room air becomes very low, that is the air
becomes chilled. Secondly, due to reduction in the temperature of the air,
relative humidity reduces.
 This air at low temperature and low humidity is sucked by the blower and it
blows it at
high pressure. The chilled air then passes through small duct inside the air
conditioner and it is then thrown outside the air conditioner through the
opening in the front panel or the grill. This chilled air then enters the room and
chills the room maintaining low temperature and low humidity inside the room.
 The cool air inside the room absorbs the heat and also the moisture and soits
temperature and moisture content becomes high. This air is again sucked by
the blower and the cycle repeats. Some outside air also gets mixed with this

20. HOT AIR CYCLE
 The hot air cycle includes the atmospheric air that
is used for cooling the condenser. The condenser
of the window air conditioner is exposed to the
external atmosphere.
 The propeller fan located behind the condenser sucks
the atmospheric at high temperature and it blows
the air over the condenser.
 The refrigerant inside the condenser is at very high
temperature and it has to be cooled to produce the
desired cooling effect.
 When the atmospheric air passes over the condenser,
it absorbs the heat from the refrigerant and its
temperature increases. The atmospheric air is already
at high temperature and after absorbing the
condenser heat, its temperature becomes even
higher. Since the temperature of this air is very high,
this is called as hot air cycle.
 The refrigerant after getting cooled enters the
expansion valve and then the evaporator. On theother
hand, the hot mixes with the atmosphere and then the
fresh atmospheric air is absorbed by the propeller fan
and blown over the condenser. This cycle of the hot
Setting the Room Temperature
with
Thermostat
 The temperature inside the room can be set by
using the thermostat knob or the remotecontrol.
 When the desired temperature is attained inside the
room,the thermostat stops the compressor of theAC.
 After some time when the temperature of the air becomes
higher again, the thermostat restarts the compressor to
produce the cooling effect.
 One should set the thermostat at the required
temperature and not keep it at very low temperature to
avoid high electricitybills.
Air Filter
The filter is a very important part of the AC since it cleans the
air before it enters the room. For proper functioning of the
filter it isvery important to clean it every two weeks.

21. 22
 These are kits of 2 units, one internal and another
external.
SPLIT AC
 The indoor unit installed inside a room intakes warm air and throws in
cold air.
 The outdoor unit on the other hand is installed out of the house. It
contains the compressor and is linked to the internal unit via drain
pipes and electric cables.
 This external unit throws out the warmair.
 Split air conditioners are used for small rooms and halls, usually in
places where window air conditioners cannot be installed. However,
these days many people prefer split air conditioner units even for
places where window air conditioners can be fitted.
 The split air conditioner takes up a very small space of your room,
• looks aesthetically cool and makes very little noise.
Advantages
 Internal unit takes up less space for
installation
 Usually more silent than window ACs
 Minimally affect your home decor
 Can be installed in room with no windows

22. There are two main parts of the split
air conditioner. These are:
1) Outdoor unit:
 This unit houses important
components of the air
conditioner like the compressor,
condenser coil and also the
expansion coil or capillary tubing.
 This unit is installed outside the
room or office space which is to
be cooled.
 The compressor is the maximum
noise making part of the air
conditioner, and since in the split
air conditioner, it
is located outside the room, the
major source of noise is
eliminated.
 In the outdoor unit there is a fan
that blows air over the condenser
thus cooling the compressed
Freon gas in it.
2) INDOOR UNIT:
 It is the indoor unit that produces the
cooling effect inside the room or the
office.
 This is a beautiful looking tall unit
usually white in color, though these
days a number of stylish models of the
indoor unit are being launched.
 The indoor unit housesthe evaporator
coil or the cooling coil, a long blower
and the filter.
 After passing from the expansion
coil, the chilled Freon fluid enters
the cooling coil.
 The blower sucks the hot, humid and
filtered air from the room and it blows it
over the cooling coil.
 As the air passes over cooling coil its
temperature reduces drastically and
also
loses the excess moisture.
 The cool and dry air enters the room

23.  Wall mounted
 Floor mounted/TowerAC
 Ceiling
mounted/Cassette AC
 Multi Split ACs
Wall
mounted
 Wall mounted split
ACs are the most
popular.
 The indoor unit is
placed in the room
and duct cannot be
concealed.
 It is generally for
 These are also known as floor-
standing air conditioners.
 Like split ACs, a tower AC set consists of 2
units- one internal and an external.
 However, the indoor unit doesn’t needwall
installation. It rather occupies some space
on the floor.
 Tower air conditioners usually have high
cooling capacity and suitable for very
large rooms.
 These are useful in rooms where you
cannot
mount the AC in yourwall.
 These are generally more expensive than
wall mounted ACs and hence less popular
for homes.
Advantages
 Suitable for high capacity cooling
 Ideal for large rooms at home and in
offices
 Doesn't need windows or wall
installation
Floor
23

24. 25
CEILING MOUNTED/CASSETTEAC
 These space-saving ACs are shaped like cassettes
and are
designed to be installed on ceilings.
 The panel of these air conditioners is designed to
blend with all kinds of home décor.
 They are stylish, and are known to deliver
fantastic performances.
 Most cassette type air conditioners require no ducting.
 They are perfect for large spaces where windows or
split AC may not reach out.
 They look aesthetically beautiful as the unit is
concealed, however this needs a falseceiling.
 The price for this type of AC is higher than wall
mounted or floor mounted splitACs.
 These are also known as concealed ACs.
Advantages
 Best at saving space
 Able to cool large areas where other ACs don’t reach
out

25.  Multi-splits are multiple
split ACs connected to
oneoutdoor unit.
 The indoor units can be
used individually or at the
same time as needed if
this is supported. If both
the units are used then
the capacityof the ACs
will be divided. The
fan and condenser of the
outdoor unit will be
controlled based on the
signals from indoor units.
 This primary saves cost as
instead of 2 split ACs you
can use this type ofAC.
MULTI SPLIT
ACS
25
Advantages of multi-split
ACs
 Saves installation space
 Can be used individually
or simultaneously
 Independent control
 Compact Design
 Good EER
 Saves on running costs
 Convenient andeconomical
Disadvantages of multi-split
ACs
 Expensive compared to a single
unit split AC
 Limited range of capacities and
models
 More prone to leakage as
number of indoor units increases

26. CENTRAL AIR
CONDITIONING SYSTEM
 Central air conditioning is used for cooling big
buildings, houses, offices, entire hotels, gyms, movie
theaters, factories etc.
 If the whole building is to be air conditioned, HVAC
engineers find that putting individual units in each of
the rooms is very expensive making this a better
option.
 A central air conditioning system is comprised of a
huge
compressor that has the capacity to produce hundreds
of tons of air conditioning.
 Cooling big halls, malls, huge spaces, galleries etc is
usually only feasible with central conditioning units
 central air conditioner unit is an energy moving or
converted
machines that are designed to cool or heat the entire
house.
 It does not create heat or cool. It just removes heat
from one
area, where it is undesirable, to an area where it
is less significant.
 The chilled water types of central air conditioning
plants are installed in the place where whole
large buildings, shopping mall, airport, hotel, etc,
comprising of several floors are to be air
conditioned.
 While in the direct expansion type of central air
conditioning plants, refrigerant is directly used to
cool the room air; in the chilled water plants the
refrigerant first chills the water, which in turn
chills the room air.
 In chilled water plants, the ordinary water or brine
solution is chilled to very low temperatures of
about 6 to 8 degree Celsius by the refrigeration
plant.
 This chilled water is pumped to various floors of
the building and its different parts.
 In each of these parts the air handling units are
installed, which comprise of the cooling coil,
blower and the ducts. The chilled water flows
through the cooling coil. The blower absorbs
CHILLED WATER CENTRAL
AIR CONDITIONING

27. 28
Chilled Water
Central Air
Conditioning

28. Key differences between "Window", "Split" and a "cassette" air
conditioners
AC Parameters Window AC Split AC Cassette AC
Suitable For Small rooms with a window
sill
Any room with or
without a window
Large indoor spaces
Noise Relatively on the higher Minimal noise Silent operation
Capacity range 0.75 ton to 2 ton 0.8 to 2 ton 1 ton to 4 ton
Advanced features Humidity control, dust filter Humidity control, dust
filter, bacteria filter
Humidity control, dust
filter, bacteria filter
Interference with home
decor
Slight possibility to
interfere with window
curtains and drapes
Designer indoor units
blend well with wall
decor
Barely interferes with
interior decor
Ease of installation Minimal effort required Indoor and outdoor units
need some amount of
effort for installation
Needs specialised
false ceiling

29. The cooling capacity is the most important feature of an air conditioner,
this primarily defines the price of the AC. Most air conditioners are rated
by tonnage. One ton is equal to 12,000 BTU per hour. The cooling
capacity needed depends on factors like:
 Size of the room: The cooling capacity required depends on the
area of the room where the AC will be installed.
 Average ambient temperature: Higher temperature of the air
outisde your house, higher is the cooling capacity needed.
 Number of people: The more the people that will be in the room,
the higher will be the cooling capacity required.
 Exposure: Direct exposure of any wall of the room to sun leads to
higher requirement in cooling capacity. Glass windows which let
sunlight inside the room also increases the need for cooling
capacity.
 Proximity of your room to kitchen: If the room is close to the
kitchen the cooling capacity needed would be higher due to higher
temperature of the kitchen.
Rooms Size (Sq
ft)
T
onnage
Capacity
Up to 90 sq ft 0.8 Ton
Up to 120 sq ft 1.0 Ton
Up to 180 sq ft 1.5 Ton
Up to 220 sq ft 2.0 Ton
30

30. 31
 Today's best air conditioners
use 30% to 50% less
energy than 1970s
 Even if your air conditioner is
only 10 years old, you may
save 20% to 40% of your
cooling energy costs by
replacing it with a newer,
more efficient model .
ENERGY
EFFICIENCY
Energy Consumption
 Air conditioners are rated by the
number of British Thermal Units
(Btu) of heat they can remove
per hour. Another common
rating term for air conditioning
size is the "ton," whichis 12,000
Btu per hour.
 Room air conditioners range
from
Energy Efficiency Ratio
 EER represents the amount of cooling an air
conditioner can provide per watt of electricity it
consumes.
 Bureau of Energy Efficiency rates air conditioners on
its star rating based on EER of air conditioners.
 Higher the EER of air conditioner higher the star ratingit
will
have.
 So a 5 star rated air conditioner provides more cooling per
watt of electricity used.
 For central air conditioners, it is the Seasonal Energy
Efficiency
Ratio, or SEER
Energy Saving Methods
 Locate the air conditioner in a window or wall area
near the center of the room and on the shadiest side
of thehouse.
 Minimize air leakage by fitting the room air conditioner
snugly into its opening and sealing gaps with a foam
weather stripping material.

31. 32
Some AC
brands
Voltas
Samsu
ng
Daikin
LG
Whirlpoo
l
Vidiocon
Bluestar
Hitachi
Haier
O general