High temperatures in summer also bring heat into the interior of cars. Air conditioning is a remedy. It is not a superfluous luxury, but a major contributor to safety. The most important questions and answers.
Pleasant temperatures in the passenger compartment make driving more comfortable – and safer
For a long time, it was considered a luxury that could be dispensed with, but today it is standard equipment in every car: the air conditioning system. The air conditioning system now not only regulates the temperature, but also ensures clean air, creating a pleasant climate on board on both hot and cold days and making a significant contribution to driving safety. In many vehicle classes, the absence of an air conditioning system in a used car is considered to have a significant negative impact on the value of the vehicle. But not all air conditioners are the same. Even if the functional principle is identical, there are differences in terms of comfort and cost, as always.
How does an air conditioner work in a car??
The air conditioning system in a car works in much the same way as the refrigerator at home. From a physical point of view, both are power-heating machines that transport their energy from one place to another in a closed circuit. Whereby the refrigerant gas used for this purpose – contrary to what the designation suggests – does not provide the cooling, but only serves as a means to an end. It is compressed in the compressor, which heats it up. The gas then passes into a condenser, where it cools down again and changes from a gaseous to a liquid state. After a dryer has filtered any condensed water out of the now liquid refrigerant, an expansion valve opens the flow to the so-called evaporator. Here it literally releases pressure and returns to its gaseous state. Now comes the decisive moment. This is because heat is drawn from the ambient air to change the state of the unit, which is then cooled considerably and blown into the vehicle’s interior via the air vents. Not before a series of filters catch foreign bodies, pollen and pollen dust. The refrigerant gas is then sucked in again and the cycle starts all over again.
Bells and whistles or safety feature?
Air conditioning is not only a comfort feature, it also makes a significant contribution to safety and accident prevention. Studies conducted by the wuppertal University of Applied Sciences on behalf of the German Federal Highway Research Institute (bast) have shown that the average number of accidents in urban areas rises by up to a third when the temperature in the vehicle interior approaches 37 degrees Celsius. When the temperature inside the vehicle rises, the physical strain becomes so great that the driver’s ability to concentrate and react can diminish dramatically. Even a two-hour drive in a non-air-conditioned car can affect the driver as much as having alcohol in the blood. The air conditioner keeps your head cool here. And those who can concentrate on traffic also avoid accidents. By the way, an air conditioner not only cools the air, but also dries it. In this way, it prevents fogged windows in autumn and winter, ensures a clear view and thus also provides more safety.
Manual air conditioning or automatic air conditioning?
In everyday language, they are often not distinguished, but in terms of function and comfort, they are two completely different systems. Whereas a manual air conditioning system only regulates the air at a set level, which has to be readjusted depending on the rise or fall of the external or internal temperature, the sensor system of an automatic air conditioning system takes over these tasks. As soon as it registers a deviation from the set number of degrees, the system regulates according to. This even works depending on the position of the sun. In newer systems the temperature can also be set in half degree increments. In addition, the more targeted regulation of the temperature reduces the risk of catching a cold.
In addition to being more convenient to operate, automatic air conditioning is also more efficient and fuel-saving than the manual system, because its targeted interventions avoid the often unnecessary constant operation of the system. The two-zone automatic system, in which the driver and front passenger can set the temperature individually, is commonly used. In higher-priced models, however, there are also multi-zone systems that allow even the backseat passengers to regulate the temperature to their liking. Everything – as always – a question of price.
How to operate my air conditioner correctly?
An air conditioner only works as well as you use it. Therefore, even before starting the car in summer, let the accumulated heat in the car escape by opening the doors and windows. Only then turn on the air conditioning and close the windows and sunroof. Afterwards, open the doors as seldom or briefly as possible. In the first few minutes, recirculating air operation is advantageous because once cooled, indoor air is cooled to the desired temperature more quickly and with less energy expenditure than warm outdoor air. This also reduces the strain on the pollen filter, which then needs to be cleaned or replaced less frequently.
the temperature in the interior should not be too low and should not be more than five to six degrees celsius below the outside temperature. "refrigerator temperatures" not only drive up fuel consumption. They can also cause circulation problems when the occupants are confronted with the hot summer air from a supercooled car. Five to ten minutes before the end of the journey, the air conditioning should be switched off. This prevents residual moisture on the evaporator and counteracts the formation of germs.
What to do if the air conditioner stinks?
Unpleasant to foul odors are usually caused by mold, bacteria and other microorganisms that have settled in the ducts, evaporators, blowers and ducts of the air conditioning system. pollen and pollen dust also collect in the filters over time and become mouldy. High time to visit a workshop. Besides changing the cabin filter, a professional treatment with ozone eliminates all bacteria, mold and fungi.
Special cleaning foams and sprays are also available in specialist shops, which you can use to disinfect your air-conditioning system yourself, provided you have a little skill and knowledge. This is how the foam is sprayed directly into the evaporator in the engine compartment and, after a short reaction time, evenly distributed throughout the system with the air conditioner turned up to full blast. The spray, on the other hand, must evaporate completely inside the vehicle with the engine running, the windows closed and the air circulating (without occupants, of course).
Do air conditioners make you sick?
"please turn off the air conditioner. I’m going to catch a cold, sniffle, whatever."many people complain that air conditioning makes them sick, based on the mistaken assumption that subjective cold, drafts or hypothermia alone are causes of a cold. In fact, air conditioning removes moisture from the air, which tends to dry out the mucous membranes in the throat and nasopharynx, making them susceptible to bacterial and viral infections. It is therefore recommended to drink regularly and sufficiently in air-conditioned interiors. In addition, air conditioning systems can become breeding grounds for bacteria and mold over time. Regular disinfection (see above) of the entire air-conditioning system and replacement of the cabin filters allow those with weak immune systems and allergies to breathe easier.
What to look out for in terms of maintenance and care?
Once a year, at least every two years, the air conditioner should be checked in a professional workshop to prevent expensive repairs. The best time to do this is, of course, in the spring – before the outside temperatures rise. Because it operates under constant pressure, all components of the air conditioning system, especially the compressor and dryer, can wear out over time.
However, at the latest when the cooling capacity decreases, the system should be checked as soon as possible for a loss of coolant. Otherwise the risk of expensive consequential damage increases. Because the coolant also lubricates the compressor. But if the compressor breaks down, costs of more than 1,000 euros can quickly become due. But even without leaks, air conditioners lose coolant as hoses and seals age, dry out, and leak. Up to 10 percent of the refrigerant escapes annually through natural evaporation. In addition, the coolant must be disposed of and, depending on the vehicle, is a very hazardous substance. Checking the system at an authorized workshop is also an important contribution to environmental protection.
The air conditioning system consumes more fuel?
Air conditioning comfort costs money and energy. Not only are the automatic systems usually not available without extra charge. The operation of an air-conditioning system is also always associated with additional consumption. Because the air-conditioning compressor is driven by a belt on the engine, the machine always takes an extra sip from the bottle. The difference between the outside temperature and the desired inside temperature is more important than the speed. But the size of the car, i.e. the interior, the type and size of the glazing, the engine itself, and its operating conditions also play a role. But there are also big differences between city and intercity travel. The bottom line is that the additional consumption varies between 0.3 and more than one liter per 100 kilometers. By the way, fuel consumption is highest in percentage terms when the vehicle is idling.
Regular operation prevents expensive repairs
As already mentioned, manual systems consume more than automatically controlled systems, which vary the cooling capacity only temporarily and as needed after the desired temperature has been set. As described above, the higher fuel costs are compounded by workshop costs for maintenance or wear and tear. However, this should not tempt drivers to switch off the system permanently for fear of high operating costs. In the long term, non-use can cause wear or even damage to the compressor. And then it gets expensive again.