Climate Control Systems

Your car’s air conditioner

The climate control system (air conditioner and heater) in automobiles is a very complex system. The systems designed into today’s cars are frequently more complex than the systems within our homes. In newer cars, the systems operate in tandem. While you may have selected air conditioning to cool the car, your heater may be operating at the same time. There are a myriad of different sensors to meter the system’s performance and operation, dependent upon driving conditions. For both fuel economy and costs savings, aluminum and other alloys or plastics are also incorporated into its design.

Operation of the air conditioner begins with the compressor. When the air conditioner is switched on (manually or automatically), the engine is commanded to spin the compressor. The compressor then compresses the freon gas inside this sealed system and circulates it through all the different components of the system. Compression of the gas results in pressures within the system. Fluctuation of pressures on the mechanical components place the greatest stress on the system. Pressures within the system may range from a low of 40 psi, up to 300 psi, and even higher in severe conditions. This results in higher engine temperatures and significant expansion and contraction of the mechanical-components. Coupled with these demands, we have a system that is expected to endure stop-and-go traffic, potholes, and extreme ambient temperatures. Along with the mechanical components, there are sensors to read pressures, throttle demands, barometric pressures, vent selection, and multiple in-car temperature sensors for automatic climate control of different locations within the vehicle. The system’s operation is commanded by a (control unit) computer subjected to all of these same extremes.

In an attempt to lower exhaust emissions and increase fuel economy, today’s cars operate at significantly higher engine temperatures. These higher temperatures place the greatest stress on the myriad of components within the climate control systems. Though lighter than the coppers and steels used in earlier designs, the use of aluminum doesn’t necessarily offer the same durability and reliability. Consequently, the benefit of these costs savings may adversely affect the life expectancy of this complex system.

The most frequent failure experienced in the climate control system is in the air conditioner. Failure is usually a result of freon loss, (loss of pressure) in the system. Lack of cooling performance is most notable in hotter weather or when sitting in bumper to bumper traffic. Usually, there is a noticeable cycling of the compressor. You may feel the idle change or surging of the engine speed as it cycles off and on. If you notice a more frequent cycling of the compressor along with less cooling, you have a failure in the system. It may be loss of freon, or it could be component failure causing erratic or incorrect pressures in the system. Continued operation may result in further wear and damage to the system. It’s time for service! Contact EuroWerks to schedule diagnosis and repair.