The interiors of modern vehicles are still very poorly thermally insulated, a quick improvement can be brought by the use of double glazing with an insulating layer of air between them. The solution has been known for years, but it does have two major disadvantages in motor vehicles. The first is the higher production cost of this type of glass, the second is their greater thickness, and so the mass. Technological and economic reasons make, that only manufacturers of higher-class cars decide to install this type of glass. Few of the models yet have reflective windshields (15-30%) solar radiation and thus reducing the heating of the interior.
Let's remember, that if the car is parked for a long time on a hot summer day, the interior heats up to about 60-70 ° C. The first minutes after switching on the air conditioning require passengers to quickly adapt to rapidly falling temperatures, which may adversely affect your well-being, especially the elderly. So it would be better to cool the interior shortly before the trip. There are experiments with the use of air conditioners to drive (when the car is stationary) solar radiation energy, caught by cells on the car roof and stored in specially enlarged batteries. Another method is to "collect cold" in specially insulated storage tanks and cool the interior for several hours after the engine is turned off. In such systems, the air is not cooled directly in the evaporator, but in an exchanger fed by a liquid cooled in the evaporator. The temperature of this liquid can be lowered drastically, thanks to this, it is possible to produce surplus "cold", storage and use when the vehicle is stationary. Such devices are already used, for example, in. for air conditioning of truck cabins. In passenger cars, the problem is finding space for these additional devices.
The German company Behr has developed and implemented a four-zone air conditioning system control. A sophisticated air damper system and the use of a multi-segment heater (also assisted by an electric heater) guarantee the possibility of individual selection of parameters not only for the driver and passenger of the front seat, but also for people in the rear of the car. These systems replace the dual air conditioning systems currently used in some vans and minibuses (more expensive, bigger and heavier). Modern air conditioning systems are also equipped with effective filter systems and air quality sensors, guaranteeing automatic closing of the outside air inflow in case of its significant contamination. In the discussed situation, electronic control systems are also able to recognize the risk of misting up the windows, if necessary, the system will stop working in a closed circuit and increase the proportion of outside air. Compressors with adjustable capacity made it possible to start work on a system that automatically adjusts to changing external conditions, which will monitor not only the temperature of the interior, but also its humidity. The automatic operation of the system is realized by changing the temperature of evaporation of the medium working in the air-conditioning circuit. Excessive precipitation of moisture and air drying during the operation of a typical air-conditioning system leads to irritation of mucous membranes in many people.. The phenomenon of drying the air in the cabin occurs after 2,5-3 hours of continuous operation of the system. "Intelligent" (that is, equipped with a larger number of appropriate sensors and appropriate microprocessor controllers) air conditioning systems are also able to smoothly regulate the temperature in the upper parts of the cabin depending on the intensity and direction of sunlight.