translated from Spanish: Why does the air conditioner in my car have a bad smell?

Although summer has passed and winter is approaching, the air conditioning system can be used all year round. In fact, it is the best element to combat fogged glass in a day of high humidity or rain. Although when it is turned on it can provide a bad smell to the cockpit, more than anything in the cars that already have some years of use.

It is not recommended to always use it at full power.

This situation does not come from the outside, but is produced in the same system of air conditioning and it is very feasible to be generated by the accumulation of moisture in the conduits over time. The air conditioner evaporator extracts the heat from the air that collects from the outside, and with the circulation of the cold liquid gas, plus a fan, allow the cooling of the cockpit. In this way the hot air is condensed generating this phenomenon. Perhaps one of the factors is the design and composition of the pipes, which do not eliminate the humidity at all, but it can also be the dirt of the filters. In the case of the first situation, the humidity can be trapped in the pipes. Because of this phenomenon, they make their appearance the mold and the bacteria that increase the bad smell, which in turn can lead to the discomfort of the occupants by means of cough, burning in the eyes and allergies. On the other hand, air conditioning systems have a particle filter. If it is very dirty it can produce a bad smell and does not fulfil its function of purifying the air that enters the vehicle. The best way to counteract this effect is to use the air conditioner frequently, at least once a month, for five minutes. This way the air circulates without obstructions that generate a bad smell. The air conditioner must not be used at full power. Condensation will be higher with higher watering that generates moisture and accumulates. Performing proper maintenance helps to avoid this situation. Therefore it is advisable to check every 10000 kilometers the condition of the filters and make the spare parts as indicated in the manual. Source: euromasterEn This note:

Original source in Spanish