After the car is driven for a period of time, the air conditioner has a "foot odor", I think this problem should plague many car owners, this is mainly because of the bacteria in the air conditioning evaporation box in our car, and how to avoid the air conditioner blowing out of the "foot odor", has become a problem that many car owners are more concerned about.
Positive: Very effective, my car has driven 150,000 kilometers in 7 years, has always turned off the air conditioning compressor in advance, replaced an air conditioning filter in half a year, never cleaned the air conditioner, and now the air conditioning refrigeration effect is leveraged, and there is no peculiar smell!
Opposite: A few minutes before stopping, turn off the air conditioning compressor and blow the evaporation box, it is useless, but blows hot air into it, which leads to the increase of condensate and the breeding of bacteria, so there is no need to disturb yourself, it doesn't matter if you turn off the compressor or not, the car is used to drive, not to supply!
The working principle of the automotive air conditioning and refrigeration system
Before discussing this issue, we first need to understand the working principle of the entire air conditioner, so as to facilitate our next argument, the automobile refrigeration system is based on the principle of "evaporation heat absorption, condensation and heat release" to work, the whole air conditioning and refrigeration system includes compressor, condenser, drying bottle, electronic fan, drying bottle, evaporation tank, blower and expansion valve.
- Compressor: converts the evaporated low-pressure gaseous refrigerant from the evaporation tank into high-temperature and high-pressure gaseous refrigerant and enters the condenser.
- Condenser: After inhaling the gaseous refrigerant at high temperature and pressure, the electronic fan in front is activated to dissipate heat, and in the process, the gaseous refrigerant continuously dissipates heat and condenses into a liquid refrigerant.
- Drying bottle: The function of the drying bottle is equivalent to a filter, filtering out the water and impurities in the liquid refrigerant, in which the appearance of water will lead to the occurrence of the phenomenon of "ice blockage", which is what we call the frosting phenomenon of air conditioning.
- Expansion valve: At this time, the high-pressure liquid refrigerant will be throttled into a low-pressure mist liquid refrigerant by the expansion valve, and the refrigerant will be converted into a liquid state due to the temperature difference of the surrounding environment, and a large amount of heat will be absorbed in the process, so the temperature of the evaporation tank will be very low.
- Blower: The air from the blower is cooled through the evaporation box, and then blown to every corner of the car through the air conditioning pipe, so as to achieve the effect of refrigeration.
This is the working principle of the vehicle air conditioning and refrigeration system, so let's discuss whether turning off the air conditioning compressor a few minutes before turning off the engine can avoid the generation of air conditioning odors?
What happens when the car air conditioning compressor is turned off?
When we turn off the air conditioning compressor, the gaseous refrigerant in the evaporation tank is still absorbing heat, and this process lasts about a minute, which is why we can still blow cold air after turning off the air conditioner.
In this process, there is still a certain temperature difference between the evaporation box and the surrounding ambient temperature, so water droplets will continue to condense on the surface of the evaporation box, which is what we call condensation, and it is also a "hotbed" for bacterial growth.
Turning off the air conditioner compressor before turning off the engine outweighs the disadvantages
In fact, in the final analysis, the generation of air conditioning odor depends on the amount of condensate and the time of existence, so as a car owner, we only need to dry the surface of the evaporation box and the condensate in the evaporation box shell as much as possible in a very short period of time, and in response to this problem, many designers of high-end models have long taken into account, in the vehicle settings, you can let the vehicle after the engine is turned off, the air conditioning blower continues to work for a few minutes, so as to achieve the purpose of drying the evaporation box, so for all car owners, it is still very necessary to turn off the air conditioning compressor before turning off the engine。
When we turn off the air conditioning compressor, because of the temperature difference, there will be water droplets near the air conditioning outlet, which will flow back into the air conditioning duct and easily breed bacteria.
At this time, you can turn off the engine and lock the car, so that you can avoid the odor of the air conditioner to the greatest extent, and we had better check our air conditioning filter every six months.
summary
Objectively speaking, the breeding of bacteria on the air conditioning evaporation box is inevitable, but we can artificially prolong the time of air conditioning odor, after all, "foot smell" is really painful, and 4S shop or auto repair shop for the treatment of air conditioning odor, it is recommended to clean the air conditioner, as little as two or three hundred, more than one or two thousand, and the effect is not satisfactory, so how to maintain a car is really important!