In the meantime, the air-conditioning system is almost standard equipment in new cars, even in our widths. How useful this is, can confirm anyone who has ever driven in midsummer at 30 degrees outside temperature and intense sunlight, a few hours. The attention decreases, the pulse goes up and it puts a lot of strain on the body.
- Manual air conditioning systems: temperature, blower level, air distribution must be set and corrected manually
- Temperature controlled air conditioners: the temperature can be selected and is maintained
- Fully automatic air conditioners: temperature (once selected), fan speed, air distribution are controlled automatically.
The function of the air conditioner
Basically, no cool air is brought in the vehicle interior, but the warm interior air is transported away. A pressurized coolant circulates in a circuit and constantly changes state between "gaseous" and "liquid" and "liquid. The refrigerant absorbs the heat of the interior, transports it away and then releases it again.
The basic structure and function of the car air conditioner should be known a little before making major repairs.
The tasks and function of the individual components of the air conditioning system
- 1 the electric magnetic switch, – disconnects the pulley drive from the compressor. The air conditioner is switched on and off like this.
- 2 the air conditioning compressor, – sucks in and compresses the gaseous refrigerant and directs the now heated medium to the condenser.
- 3 the condenser, – cools the heated refrigerant by means of airstream, and
8 additional fans off, making it liquid.
- 4 the dryer, – dries and filters the refrigerant and serves as a supply reservoir.
- 5 the expansion valve, – injects the refrigerant in the required amount, into the evaporator, which greatly reduces the pressure.
- 6 in the evaporator, – because of the low pressure and the intrinsic heat, the refrigerant gasifies and cools down. Due to the large surface area of the evaporator, sufficient heat is always supplied.
- The blower motor, -ensures that there is always enough warm air from the passenger compartment supplied to the evaporator.
- Now the gaseous refrigerant is sucked back in by the compressor and the cycle starts all over again.
The air conditioner does not cool, or cools insufficiently, poorly
The only thing you can do yourself is to check the electrical fuses, then you have to go to a garage first. Mostly only coolant is missing -which has to be refilled every two to three years. In ca. 90% of the cases, the error is already eliminated with it.
However, care should be taken to ensure that a contrasting agent is added at the same time as filling. If after a few days, the air conditioning is no longer working properly, the leak can be found quickly.
If the system pressure is correct, all the fuses are intact and the car air conditioning still does not work, a very common fault is that the solenoid, the magnetic ring on the air conditioning compressor no longer attracts. How to check and replace the solenoid coil of the air conditioner, for this I have created an extra repair manual.
Is air conditioning maintenance, air conditioning check really useful and necessary?
Is air conditioning maintenance really necessary and what should be done??
Many contract and independent auto repair shops offer air conditioning maintenance, air conditioning check or whatever else they call it, for expensive money and talk their customers into it as absolutely necessary.
Some clarification is needed:
there is no car manufacturer that recommends or prescribes an air conditioning check or maintenance work on the air conditioning system!
Why not? The car air conditioner is a closed system in which the coolant mixed with a lubricant circulates during operation. If the system is tight, nothing needs to be done to it. No one changes the coolant from his refrigerator at home!
But of course, the air conditioning system in the car is also exposed to more extreme conditions, which make failures more likely.
The cabin air filter, also known as a pollen filter, is changed as part of the inspection. Fig.2
if the air conditioner cools correctly, there is absolutely nothing to do.
However, the car air conditioner loses some coolant over the years and the cooling capacity decreases. However, every car driver notices this in exactly the same way as he notices that the heating does not warm up properly.
Only then is a visit to the garage necessary so that the coolant is renewed. Fig3 + fig4
it makes sense to fill in a contrast medium with the coolant at the same time, so that possible larger leaks can be found more easily if the pressure drops too quickly.
A new filling of the air conditioner is usually necessary only after 2-4 years, -when the cooling performance has become poor.
Run the air conditioner at least once a month, even in winter. The purpose of this is to ensure that the lubricant in the air conditioning system is well distributed again and that the seals do not become brittle.
If the air conditioner stinks
My car air conditioner stinks, what to do??
Provided that the cabin filter is replaced at least once a year, in most cases, a simple change in the operation of the air conditioner will remedy the situation.
Many drivers set the air conditioner on full blast or automatic and turn off the car immediately when they reach their destination.
What happens? The air conditioner, the heating box, the air hoses, etc. Are ice cold. After shutdown, the humidity immediately settles on all components. It fogs up like a beer glass filled with cold delicious beer. See fig5.
In this -always recurring- moisture, fungi and bacteria settle, which then trigger the odor nuisance.
Turn off the air conditioner a few minutes before reaching your destination and leave the fan running. This way, all components return to the ambient temperature and nothing can fog up again.
A very nice side effect is; you use the residual coolness in the system and save even fuel!
I have recommended this behavior to many of my customers and the smell was always gone after a few days. Disinfection was not necessary in any case, -because without moisture there is no fungus or bacteria.
No car manufacturer requires maintenance work on the car air conditioning system!
Be suspicious if the garage wants to sell you an air conditioning service, an air conditioning check and/or an air conditioning disinfection. Some also like to immediately replace the air conditioning evaporator.
Whoever sells such things may also like to sell other useless expensive stuff.
Still questions about these topics? Ask your questions in our car forum.
Most images can be enlarged by clicking on them.
Abb2 cabin air filter (pollen filter) is often moldy
Fig3 air conditioning service unit, for filling air conditioning systems
Fig4 connections for filling the air conditioning system in the vehicle
Fig5 in several self-experiments, the fogging of the humidity was determined on a beer glass to illustrate this.
Timing belt replacement made easy
with pictures and graphics
The air conditioner compressor
The fuse of the magnetic ring is defective
MKL lights up! ignition misfire cylinder 2 found! Error code P0302
Read out error codes yourself with app here
Various television appearances by hannes, here filming
with sat1 for a report