You credibly do n’t think of your car ’s aviation conditioning organization very often . But if it dampen down , you ’d emphatically miss the cool tune . So , how does AC influence in a machine ?
A Brief History of Car Air Conditioning
Automotive air conditioning has been with us longer than you might think . Packard invented automotive AC all the room back in 1939 , and in 1940 it was the first gondola company to offer factory - installed air conditioning .
Of course , this early system did n’t have a thermostat , but it was better than not having anything at all . The estimate caught on , and by 1969 , more than one-half of all novel elevator car were sold with air conditioning build up in .
Car Air Conditioning and Global Warming
Eventually , it was dictated that the refrigerant used for decade in automotive AC , bang as R-12 , CFC-12 , or its steel nameFreon , was damaging the ozone layer ( it ’s a CFC ) .
It was banned from being fabricate in the United States and an choice , call R-134a or HFC-134a , was want for all cars make up after 1996 .
Beginning in 2012 , the Environmental Protection Agency ( EPA ) began phase in a new , sound - for - the - environment refrigerant known as R-1234yf or HFO-1234yf . According to theEPA , R-1234yf has a global thawing potential ( GWP ) of 4 , compared to R-134a ’s GWP of 1,430 .
In 2022 , 97 percent of new fomite in the U.S. used the new refrigerant .
How Does AC Work in a Car?
A car ’s air conditioning work by manipulate pressure and temperature to move refrigerating between a smooth and gaseous state . The refrigerant enters the evaporator as a liquid , and the oestrus of the auto metamorphose it into a gas pedal . In its gaseous state , refrigerant can absorb heating .
The refrigerant is advertise out of the car , move out live air from the vehicle and bringing it back to the compressor , where it is pressurized back into a liquidity to start the process over again . There ’s also a buff outside the evaporator compartment , which blows cool airwave into the passenger cabin .
Components of A Car AC System
All automotive air conditioning system are ( nearly ) shut down loops with a high - pressure side and low - pressure side . Starting at the mellow - pressure side , let ’s take a look at what happens within each element of a car ’s line conditioner :
The Compressor
The compressor is a ticker driven by a belted ammunition impound to the engine ’s crankshaft . When the refrigerant is drawn into the compressor , it is in a low - air pressure gaseous form .
Once the gas is inside the pump , the compressor be up to its name . The belt drive the pump , which puts the gas under pressing and force it out to the optical condenser . Compressors can not compact liquids , only gasses .
The Condenser
The condenser is essentially a radiator , and it service the same function as the one in your home : to radiate heat out of the system . The refrigerant enters the condenser as a pressurized gas pedal from the compressor .
The process of pressurizing the gas pedal and moving it to the condenser create heat , but air flowing around the twisting tubes of the electrical condenser cool the refrigerant down until it forms a liquid again .
Imaginesteamcooling down and condense back into water , and you ’ve take the idea . The melted refrigerant is now a high - atmospheric pressure liquidness and closely ready to cool the railcar .
The Receiver-Dryer
As it be active out of the condenser , the liquid goes through a slight artificial lake install in the railway line . This receiver - dryer contains desiccants , small granules that attract body of water .
You ’ve seen packets of drier in shoeboxes , where they do the same thing : appeal urine from the air to keep unexampled shoe reinvigorated and quick for your feet . ( They ’re unremarkably judge : " Do not eat . " )
In the liquidator - drier , they bump off any water that has entered the organization . If the piddle is allowed to remain and possibly work methamphetamine hydrochloride crystal , it can damage the line conditioning system .
Thermal Expansion Valve (TXV)
Here , the system changes from the high-pitched - pressure side to the humiliated - pressure side . If you were to partake this part of the organization , you ’d feel it change from hot to cold .
The high - press liquid refrigerating flows from the receiver - dryer through the enlargement valve , where it is allowed to expand . This expansion reduces the insistency on the refrigerant , so it can move into the evaporator .
The valve senses pressure and baffle the flow of refrigerant , which give up the organization to operate steadily , but the go parts of the valve can bear out and sometimes require replenishment .
Some vehicle have an opening electron tube rather than an expansion valve , but it swear out the same intent in allowing the refrigerant to expand and the pressure to be glower before the liquidity enters the evaporator .
The opening electron tube earmark refrigerant to flux at a constant rate and has no moving part , but it can become clogged with debris over time . Systems with an orifice thermionic vacuum tube automatically turn the AC system on and off to influence the flow of refrigerant to the evaporator .
Evaporator
This is where the illusion happen . While all the other part of the system are located in theenginecompartment , this one is in the cabin , usually above the footwell on the passenger side . It also await like a radiator , with its gyre of tube-shaped structure and fins , but its job is to absorb hotness rather than dissipate it .
Refrigerant enter the evaporator coil as a cold-blooded , miserable - pressure liquid , ideally at 32 degrees Fahrenheit ( 0 degrees Celsius ) , which is why you do n’t want any water in the system . The refrigerant does n’t block at this temperature , but it does have a very low simmering item .
The heating in the cabin of the automobile is enough to make the refrigerant in the evaporator boil and become a gas again , just like water turning back to steam . In its gaseous form , refrigerant can steep a mountain of heat .
The gas moves out of the evaporator and out of the passenger compartment of the car , taking the passion with it . A fan blow over the exterior of the evaporator coil blows cool gentle wind into the passenger compartment .
The refrigerant in gas form then enters the compressor , where it is pressurize and the whole process starts all over again .
If the system apply an orifice tube , there will be an accumulator between the evaporator and the compressor . An opening pipe sometimes lets too much refrigerating into the evaporator , and it does n’t all boil . Since the compressor can not compress liquidity , only throttle , the accumulator trap any extra liquid state before it can get into the compressor .
The evaporator also takes humidity out of the air in the car , which helps you finger cool . Water in the air condenses on the evaporator coil , along with stain andpollenand anything else floating around in the cabin .
When you stop the railway car and see water drop underneath , it ’s believably the water from the AC evaporator and nothing to worry about .
