basic mechanical engineering - air conditioning
TRANSCRIPT
Prepared by
MSSteve
Assistant Professor
Dept of Mechanical Engineering
Amal Jyothi College of Engineering
Kanjirapally
Air conditioning
msstevesimongmailcom
Page 2
Definition
Process of treating the air so as to control simultaneously its
temperature humidity purity and distribution to meet the
requirements of controlled space
Requirements of a conditioned space
1 Comfort and health of occupants
2 Needs of certain industrial processes
3 Efficient working of commercial premisesoffices
msstevesimongmailcom
Page 3
Air conditioning
For human comfort air should have the following
properties
1 Temperature -22 degC to 27 degC
2 Humidity - 55 to 65 Relative Humidity
3 Velocity - 03 -05 ms
Air conditioning systems coolheat the air
humidifydehumidify the air to the above human
comfort conditions depending on the temperature
and humidity of the outside atmospheric air
msstevesimongmailcom
Page 4
Applications
Industrial applications- To control chemical amp bio
chemical reactions
Commercial applications- Theatres hotels banks
etc
Transport applications ndash automobiles aircraftsships
etc
Special applications ndash T V centres hospitals
computer centres etc
msstevesimongmailcom
Page 5
Classifications
Depending up on the processes required for conditioning of
outside air air conditioning system are classified in to
1 Summer air conditioning- it involves Cooling amp
Dehumidification process
2 Winter air conditioning ndash it involves Heating amp
Humidification process
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 2
Definition
Process of treating the air so as to control simultaneously its
temperature humidity purity and distribution to meet the
requirements of controlled space
Requirements of a conditioned space
1 Comfort and health of occupants
2 Needs of certain industrial processes
3 Efficient working of commercial premisesoffices
msstevesimongmailcom
Page 3
Air conditioning
For human comfort air should have the following
properties
1 Temperature -22 degC to 27 degC
2 Humidity - 55 to 65 Relative Humidity
3 Velocity - 03 -05 ms
Air conditioning systems coolheat the air
humidifydehumidify the air to the above human
comfort conditions depending on the temperature
and humidity of the outside atmospheric air
msstevesimongmailcom
Page 4
Applications
Industrial applications- To control chemical amp bio
chemical reactions
Commercial applications- Theatres hotels banks
etc
Transport applications ndash automobiles aircraftsships
etc
Special applications ndash T V centres hospitals
computer centres etc
msstevesimongmailcom
Page 5
Classifications
Depending up on the processes required for conditioning of
outside air air conditioning system are classified in to
1 Summer air conditioning- it involves Cooling amp
Dehumidification process
2 Winter air conditioning ndash it involves Heating amp
Humidification process
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 3
Air conditioning
For human comfort air should have the following
properties
1 Temperature -22 degC to 27 degC
2 Humidity - 55 to 65 Relative Humidity
3 Velocity - 03 -05 ms
Air conditioning systems coolheat the air
humidifydehumidify the air to the above human
comfort conditions depending on the temperature
and humidity of the outside atmospheric air
msstevesimongmailcom
Page 4
Applications
Industrial applications- To control chemical amp bio
chemical reactions
Commercial applications- Theatres hotels banks
etc
Transport applications ndash automobiles aircraftsships
etc
Special applications ndash T V centres hospitals
computer centres etc
msstevesimongmailcom
Page 5
Classifications
Depending up on the processes required for conditioning of
outside air air conditioning system are classified in to
1 Summer air conditioning- it involves Cooling amp
Dehumidification process
2 Winter air conditioning ndash it involves Heating amp
Humidification process
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 4
Applications
Industrial applications- To control chemical amp bio
chemical reactions
Commercial applications- Theatres hotels banks
etc
Transport applications ndash automobiles aircraftsships
etc
Special applications ndash T V centres hospitals
computer centres etc
msstevesimongmailcom
Page 5
Classifications
Depending up on the processes required for conditioning of
outside air air conditioning system are classified in to
1 Summer air conditioning- it involves Cooling amp
Dehumidification process
2 Winter air conditioning ndash it involves Heating amp
Humidification process
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 5
Classifications
Depending up on the processes required for conditioning of
outside air air conditioning system are classified in to
1 Summer air conditioning- it involves Cooling amp
Dehumidification process
2 Winter air conditioning ndash it involves Heating amp
Humidification process
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 6
Winter air conditioning
In winter outside temperature is low hence heating of air is
needed for comfort
Cycle of operations consists of
1 Air cleaning
2 Air heating
3 Humidification
4 Air distributioncirculation
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 7 msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 8
Winter air conditioning system
The outside air is sucked in through the damper and is
filtered using an air filter
The air is then passed through a preheat coil to heat the
air to control the evaporation of water in the humidifier
Steam is mixed with the air in required quantity to
increase the humidity to 55 RH
The air is then passed through a reheat coil to bring it to
the comfort temperature of 22 degC
The conditioned air is then supplied to the conditioned
space by a blower
Cold polluted air is discharged out and outside air is
again sucked to repeat the cycle
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 9
Winter air conditioning system
These systems are used to heat the air and
increase the humidity to acceptable levels
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 10
Summer air conditioning
In summer outside temp is more and hence cooling of air is
required
Consists of
1 Air cleaning
2 Air cooling
3 Dehumidification
4 Air distributioncirculation
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 11 msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 12
Summer Air Conditioning
In this system air is cooled amp dehumidified
The outside air flows through the damper and is filtered
using the filter
The air is then passed through a cooling coil and the air
gets cooled below the required temperature and is also
dehumidified
The cooled air is then passed through the water
eliminator and water is collected in the sump
After that air is made to pass through a heating coil to
reach the desired comfort condition
The conditioned air is now supplied to the space using
the blower
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 13
Summer Air Conditioning
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 14
Essentials of air conditioning systems
Temperature control
Effective temp = 200C to 230C in summer
Effective Temp = 180C to 220C in winter
For Indian conditions 250C with 60
relative humidity to 300C with 45 relative
humidity with air velocity not exceeding
10 mmin
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 15
Humidity control
During summer dehumidification
is done so that relative humidity is
40 to 50
During winter humidification is
done so that relative humidity is
50 to 60
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 16
Air velocity control
High velocity of conditioned air
may cause greater temperature
difference between outside and
inside
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 17
Air quality control
Air should be free from
odour toxic gases bacteria
and other micro-organisms
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 18
Essentials of air conditioning systems
1 Filtration
2 Heating (in winter)
3 Cooling (in summer)
4 Humidification
5 Dehumidification
6 Air circulation or distribution
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 19
1 Filtration
Should be capable of removing dust ash smoke
bacteria etc
Should be capable of holding moderate amount of
dust without affecting the efficiency
Should offer low resistance to flow of air
Workable under sufficient range of velocities
Should afford easy cleaning manually or
mechanically
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 20
2 Heating (in winter)
Heating is necessary in winter so as to
compensate heat loss from room
Pre heating of incoming air may be done by
passing over air furnaces or coils through
which hot water is circulated
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 21
3 Cooling (in summer) Cooling of incoming air is
necessary in summer
Principle of mechanical refrigeration
is used
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 22
4 Humidification
Humidification or addition of water is
necessary in winter because of low
temp has less humidity
Incoming air is passed through pans of
water or wet cloth strips
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 23
5 Dehumidification
In this process certain amount of
water is extracted from air
This is done in summer where
incoming air is cooled
Adsorbents can be used to adsorb
excess moisture from air
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 24
Psychrometry
The properties of moist air are called as
pshychrometric properties
Although the principles of pshychrometry
can be applied to any physical system
consisting of gas vapour mixturesthe most
common system of interest is the mixture of
water vapour amp air
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 25
Terms used in psychrometry
Dry Air Dry air is a mixture of oxygen nitrogen carbon
dioxide hydrogen argon neon helium etc
Moist Air It is an ordinary air which is a mixture of dry
air and water vapour
Saturated Air It is the air which contains maximum
amount of water vapour which the air can hold at a given
temperature and pressure
Relative Humidity (RH) It is the ratio of mass of water
vapour in a given volume of moist air at a given
temperature to the mass of water vapour contained in the
same volume of moist air at the same temperature when
the air is saturated
Dry Bulb Temperature (DBT) It is the temperature of air
measured by an ordinary thermometer
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 26
Terms used in psychrometry
Wet Bulb Temperature (WBT) It is the temperature
recorded by a thermometer when its bulb is covered by a
wet cloth and is exposed to a current of moving air
Dew Point Temperature (DPT) It is the temperature at
which the condensation of moisture begins when the air
is cooled at constant pressure
Sensible Heat of Air It is the enthalpy of dry air which
can be calculated by measuring its dry bulb temperature
Total Heat It is the sum of sensible heat of dry air and
sensible plus latent heat of water vapour present in it
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Page 27
Psychrometric chart
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom
Thank You
M S Steve msstevesimongmailcom
msstevesimon
2mssteve
msstevesimongmailcom