A brief description and explanation of the parts and the working of an air conditioner in automobiles such as cars.

2. WHY AC SYSTEM?
Stopped in traffic on a may afternoon?
Sweat drips all over your body?
Hands feel like they are about to slip away from the
steering wheel due to sweat?
Need a luxurious and a comfortable ride?
Why don’t you attach an automotive air conditioning
system to your ride, which 99% of all new cars produced
since 2010 are equipped with?

3. HOW DOES IT WORK?
Main function- to cool and remove humidity from air
inside the car.
Parts of a typical car AC system are:
(i)Compressor (ii)Condenser (iii)Receiver or Dryer
(iv)Expansion valve (v)Evaporator

4. COMPRESSOR
It is a pump driven by a belt attached to the engine’s
crankshaft.
Puts the refrigerant gas under pressure and forces it to the
condenser.
It cant compress liquids, only gases.
By increasing the pressure the refrigerant gas leaving the
compressor becomes hot.
Also called as heart of the air conditioning system.
Earlier freons(R-12) were used as refrigerants. Nowadays
they are replaced by environment friendly HFC(R-134a).

5. CONDENSER
Identified as second radiator of the car that shares air flow
with main radiator.
Has its own cooling fans that become active when AC is
on.
Takes up the heat from the high pressure refrigerant gas
and cools it.
Condensing of the refrigerant gas causes it to loose heat
and form into a liquid.
Heat is expelled into the atmosphere by the air flowing
from the cooling fans.

6. RECEIVER OR DRYER
Small reservoir installed in the line of the condenser.
Main function is to remove moisture and other
contaminants from the cool refrigerant liquid.
Contains small granules called desiccants that attract
water.
If water is not removed, it can form ice crystals, thereby
damaging the whole system.

7. EXPANSION VALVE
Here the pressure of refrigerant is reduced causing
expansion of the liquid, resulting in further cooling.
Slowly the liquid reverts back into a gaseous form.
Also the valve reduces pressure on the refrigerant so it can
easily move into the evaporator.
The valve senses pressure and
regulates the flow of refrigerant,
which allows the system to
operate steadily.

8. EVAPORATOR
Radiator like device buried deep under the dashboard.
Refrigerant gas enters the evaporator coils and absorbs the
heat inside the car’s cabin and moves out of the coils.
A fan blowing over the outside of the evaporator coil
blows cool air into the passenger compartment.
Thus the evaporator takes humidity out of the air in the
car, which helps you feel cool.

9. SCHEMATIC DIAGRAM FOR EASY
UNDERSTANDING

10. CONCLUSION
An AC system not only cools the cabin, it removes dust
and dirt, leaving only with fresh air.
One has to remember to use only environment friendly
refrigerants and avoid CFCs as much as possible.
The AC system can be recharged by adding fresh
refrigerant and removing the remaining one.
Care must be taken in the disposal of refrigerants as they
may affect the soil, rivers, etc.,
Its also necessary to check the AC system for leaks as it
may lead to the loss of refrigerant as well as
environmental hazards.

11. Thank you…
Anyways, let us minimize the usage of ACs and go green!