air conditioning systems in refrigeration and air conditioning
TRANSCRIPT
Air-conditioning
systems
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Faculty Name: Prof. Ajaypalsinh G. BaradBranch: MechanicalSemester: 6th
Name of Subject: Refrigeration and Air Conditioning
Coverage
• Introduction
• Classification
• System components
• All air systems
• All water systems
• Air water systems
• Room air conditioners
• Packaged air conditioning plant
• Central air conditioning systems
• Split air conditioning systems2
Introduction:
• The air conditioning is defined as “ The process of
treating air in an indoor environment (room or space)
to establish and maintain required standards of
temperature, humidity, cleanliness and motion of air .”
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Introduction:
The complete process of air conditioning includes
following processes:
• Cooling or heating the air as per requirement of
temperature
• Addition of moisture in air (Humidification) or removal of
moisture from air (Dehumidification).
• Controlling movement of air (air motion)
• Purification of air (cleaning or filtering)
• Addition of fresh air from outside (ventilation)
• Distribution of air
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Classification of Air Conditioning System:
• Based on way of air cooling:
– Direct cooling system
– Indirect cooling system
• Based on major function
– Comfort air conditioning system
– Industrial air conditioning system
• Based on season of year
– Winter air conditioning system
– Summer air conditioning system
– Year round air conditioning system
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Classification of Air Conditioning System:
• Based on arrangement of equipments
– Unitary air conditioning system
• Window air conditioner
• Split air conditioner
• Package air conditioner
– Central ail - conditioning system
• All air system
• All water (hydronic) system
• Air-water system
– Zoned system
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Air conditioning system components:
• An air conditioning system is an assembly of differentparts of the system used to produce a specified conditionof air within a required space or building.
• Air conditioning system has following components:
– Cooling source
– Heating element
– Control system
– Distribution system
– Fans
– Filter
– Grille
– Tray
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Room (Window) air conditioners:
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Limitation of window air conditioner:
• It produces noise in the room because of compressor
is very near to the room.
• The evaporator and condenser is enclosed in single
unit. Therefore evaporator cannot be used as an
interior of room because condenser requires outside
air for cooling.
• It requires appropriate size of window or hole in wall
in order to fit the conditioner.
Room (Window) air conditioners:
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• First part: Includes the evaporator, filter, evaporator
fan and grille. They placed inside the room.
• Second part: Includes condenser, fan, and compressor.
This placed outside the room.
Split Air Conditioner:
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• First part: Includes the evaporator, filter, evaporator
fan and grille. They placed inside the room.
• Second part: Includes condenser, fan, and compressor.
This placed outside the room.
Split Air Conditioner:
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Advantages of Split AC over Window AC:
• The compressor is outside of the room, therefore no
compressor noise, and vibration in the room or space
to be conditioned.
• No window opening and fixing needed.
• The first part can be located in the room with
decorative display. It can be mounted on floor, ceiling,
and wall or behind a decorative structure.
Split Air Conditioner:
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The Advantages of unit:
• It is fully factory made and hence proper selection and
balance of components is possible.
• All the manufacturing and testing processes like assembly,
leak testing, processing and charging carried out under
factory conditions.
• Inspection and testing of the complete unit before it leaves
the factory. Hence, better quality is maintained.
• Delivery of unit to the site with full assembly and in
working order, hence avoiding site delays for materials.
• Fully assembled unit requires less time for installation and
hence minimum of inconvenience and cost.
Package Air Conditioning System:
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• It is fully
Summer air conditioning system:
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• It is fully
Winter air conditioning system:
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• It is fully
Year round air conditioning system:
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The system may be classified as follows:
• All air system
• All water system
• Air water system
Central air conditioning system
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• Single duct, single zone, CV
All air system
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• Single duct, Multi zone, CV
All air system
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• Duel duct, Multi zone, CV
All air system
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• Single duct, Multi zone, VAV
All air system
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Advantages:
• Possible to use a wide variety of air filters and avoid
noise in the conditioned space.
• Complete absence of drain pipes, electrical wiring, and
filters at the conditioned space.
• In case of dual duct systems, it is possible to provide
simultaneous cooling and heating.
• Seasonal change over is very simple and easy to
automate.
• Very flexible heating and cooling can occur in different
zones simultaneously
All air system
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Disadvantages:
• It requires more space, reduces the available floor
space.
• Due to space constraints it may be difficult to provide
air conditioning in high rise buildings with the plant on
the ground floor or basement.
• Due to the space requirement retrofitting may not
always be possible.
• Balancing of air may be difficult in case of large and
particularly with variable air volume systems.
All air system
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All Water system
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FCU-terminal
All Water system
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Advantages:
• The plant size is small due to the absence of large
supply air fans.
• It is easier to retrofit to existing buildings.
• The thermal distribution system requires very less
space compared to all air systems.
• In case of four pipe system, simultaneous cooling and
heating is possible.
• Solar or waste heat can be utilized for winter heating.
All Water system
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Disadvantages:
• It requires higher maintenance compared to all air
system.
• The filters are small, low in efficiency and require
frequent replacement.
• The ventilation depends on wind and hence, it is
difficult to ensure positive ventilation under all
circumstances when ventilation is provided by opening
windows or wall apertures.
• Control of humidity, particularly during summer is
difficult using chi lied water control valves.
All Water system
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Air - Water system
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• FCU for Air-Water
Air - Water system
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Advantages:
• Rooms can be individually controlled at relatively low cost,
which control either the secondary water flow rate or the
secondary air (in fan coil units) or both.
• The amount of primary air supplied is less than that of an
all air systems therefore, space requirement is reduced.
• There is no latent heat transfer is required in the cooling
coil placed in the conditioned space, and its life thereby
increases.
• Terminal units in case of induction unit does not have fans,
motors, or compressors and hence service of indoor units is
relatively simpler compared to all water systems.
Air - Water system
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Disadvantages:
• Need for handling and controlling both air and water,
operation and control are complicated.
• The water coils in the conditioned space can become dirty if
the quality of filters used in the room units is not good.
• Initial cost could be high compared to all air systems.
• Shutting down the supply of primary air to unoccupied
spaces is not possible because constant amount of primary
air is supplied to conditioned space, and room control is
only through the control of room cooling / heating coils.
Air - Water system
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