AMT 212
Air Conditioning - It controls the PACK inlet door to vary the amount
Air Supply of air passing through the heat exchanger
- The source of air to pressurize and air condition Primary Heat Exchanger (Slightly Cooled)
an aircraft varies with the engine type. - The first stage of heat exchanger
Sources of Supply Air: Heat Exchanger
A. Bleed air from the compressor - It uses the flow of ram air to cool the hot bleed air.
- It is a great source of air, for air Air Cycle Machine
conditioning and cabin pressurization
- It compresses the bleed flowing through the
during stable flights.
secondary heat exchange that cools the air again
- It is relatively free of contaminants.
with ram air.
B. Auxiliary Power Unit (APU)
Secondary Heat Exchanger
- It is designed to deliver pressurized bleed
air for engine starting and for operation of - It is the second stage of heat exchanger.
the aircraft’s air conditioning packages. - It cools the hot bleed air even further from the
- Used only when: primary heat exchanger.
• The aircraft is on ground if Bypass Valve
Ground Cart is unavailable. - It allows warmer air to mixed with the cold air.
• For emergency on flight. Mixer/Mixing Unit
C. Ground cart - It is fed by the conditioned air from the packs
- It is available to provide the pressurized source
- It may also receive conditioned air from a low-
of air for the air conditioning packs.
pressure ground connection, or in flight, fresh
- It is regulated to the normal pneumatic system outside air from the emergency ram air flap.
pressure and can also be used for pneumatic
system trouble shooting without the expense of
- It feed three separate aircraft zones, cockpit,
forward cabin, and aft cabin.
running the APU or main engines.
Cabin Recirculating Fan
Air Conditioning System
- It is fitted to reduce the bleed air requirement and
- It is used to supply conditioned air inside the cabin
therefore save fuel. These fans establish a
and the cockpit at a comfortable temperature.
recirculation flow of air from the cabin zones to the
There are two types of air conditioning systems
mixer unit.
commonly used on aircraft:
Ram Air Flap
1. Air cycle
- It prepares engine bleed air to pressurize - In flight, in case of failure of both PACKs,
the aircraft cabin emergency ventilation is provided by an
- It is often called as the air conditioning emergency ram air flap controlled by the crew.
package or pack. Hot Air Valve
- it is located in the lower half of the - It regulates the pressure of hot air supplied to the
fuselage (Belly) or in the tail section trim air system, and to act as shut-off valve.
- Bleed Air, Gas Turbine Engine Trim Air Valve
2. Vapor cycle - Hot bleed air can be added via Trim Air Valves to
- Liquid, Reciprocating Engine achieve the demanded temperature for a zone.
Air Cycle Zone Duct Temperature
Air Cycle Air Conditioning System Components - The temperature of air entering the zone
Hot Bleed Valve Zone Temperature
- It supplies hot bleed air from the aircraft’s
- The actual temperature of air in the zone
pneumatic system to the pack.
Zone Controller
Pack Flow Control Valve
- A device that monitors the temperatures of the
- It adjusts the flow rate through the pack and to
three zones and send signals to the PACK
achieve the shut-off function
Controllers to set the air temperatures delivered
Pack Controller
by the PACKs.
- It regulates the PACK flow control valve and Water Separator
Air Conditioning - It controls the PACK inlet door to vary the amount
Air Supply of air passing through the heat exchanger
- The source of air to pressurize and air condition Primary Heat Exchanger (Slightly Cooled)
an aircraft varies with the engine type. - The first stage of heat exchanger
Sources of Supply Air: Heat Exchanger
A. Bleed air from the compressor - It uses the flow of ram air to cool the hot bleed air.
- It is a great source of air, for air Air Cycle Machine
conditioning and cabin pressurization
- It compresses the bleed flowing through the
during stable flights.
secondary heat exchange that cools the air again
- It is relatively free of contaminants.
with ram air.
B. Auxiliary Power Unit (APU)
Secondary Heat Exchanger
- It is designed to deliver pressurized bleed
air for engine starting and for operation of - It is the second stage of heat exchanger.
the aircraft’s air conditioning packages. - It cools the hot bleed air even further from the
- Used only when: primary heat exchanger.
• The aircraft is on ground if Bypass Valve
Ground Cart is unavailable. - It allows warmer air to mixed with the cold air.
• For emergency on flight. Mixer/Mixing Unit
C. Ground cart - It is fed by the conditioned air from the packs
- It is available to provide the pressurized source
- It may also receive conditioned air from a low-
of air for the air conditioning packs.
pressure ground connection, or in flight, fresh
- It is regulated to the normal pneumatic system outside air from the emergency ram air flap.
pressure and can also be used for pneumatic
system trouble shooting without the expense of
- It feed three separate aircraft zones, cockpit,
forward cabin, and aft cabin.
running the APU or main engines.
Cabin Recirculating Fan
Air Conditioning System
- It is fitted to reduce the bleed air requirement and
- It is used to supply conditioned air inside the cabin
therefore save fuel. These fans establish a
and the cockpit at a comfortable temperature.
recirculation flow of air from the cabin zones to the
There are two types of air conditioning systems
mixer unit.
commonly used on aircraft:
Ram Air Flap
1. Air cycle
- It prepares engine bleed air to pressurize - In flight, in case of failure of both PACKs,
the aircraft cabin emergency ventilation is provided by an
- It is often called as the air conditioning emergency ram air flap controlled by the crew.
package or pack. Hot Air Valve
- it is located in the lower half of the - It regulates the pressure of hot air supplied to the
fuselage (Belly) or in the tail section trim air system, and to act as shut-off valve.
- Bleed Air, Gas Turbine Engine Trim Air Valve
2. Vapor cycle - Hot bleed air can be added via Trim Air Valves to
- Liquid, Reciprocating Engine achieve the demanded temperature for a zone.
Air Cycle Zone Duct Temperature
Air Cycle Air Conditioning System Components - The temperature of air entering the zone
Hot Bleed Valve Zone Temperature
- It supplies hot bleed air from the aircraft’s
- The actual temperature of air in the zone
pneumatic system to the pack.
Zone Controller
Pack Flow Control Valve
- A device that monitors the temperatures of the
- It adjusts the flow rate through the pack and to
three zones and send signals to the PACK
achieve the shut-off function
Controllers to set the air temperatures delivered
Pack Controller
by the PACKs.
- It regulates the PACK flow control valve and Water Separator
