What is the refrigerant currently used in air conditioning?
2 Answers
Currently, there are two main types of refrigerants used in automotive air conditioning systems: R12, which is non-environmentally friendly, and R134a. The selection criteria for refrigerants are as follows: 1. Consider the type of compressor. Different refrigeration compressors operate on different principles. Positive displacement compressors increase pressure by reducing the volume of refrigerant vapor, typically selecting refrigerants with high refrigeration capacity per unit volume. 2. Consider the refrigeration temperature requirements. Depending on the refrigerant temperature and cooling conditions, high-temperature (low-pressure), medium-temperature (medium-pressure), or low-temperature (high-pressure) refrigerants are chosen. Generally, the standard evaporation temperature of the selected refrigerant should be at least 10°C lower than the refrigeration temperature. The selection should also account for the cooling conditions and operating environment of the refrigeration system. The operating condensing pressure should not exceed the safety limits specified for the compressor. Automotive air conditioning systems can only use outside air as the cooling medium, and factors such as ambient temperature, wind speed, solar radiation, and heat radiation frequently change, necessitating the use of high-temperature (low-pressure) refrigerants. In the past, R12 was commonly used, but now R134a is predominantly selected. 3. Consider the properties of the refrigerant. Based on thermodynamic, physical, and chemical properties, choose refrigerants that are non-toxic, non-explosive, and non-flammable. The selected refrigerant should have good heat transfer, low resistance, and compatibility with materials used in the refrigeration system. 4. Consider environmental requirements. The refrigerant must comply with national environmental regulations.
I just went to the repair shop to address an air conditioning issue and learned that the mainstream automotive refrigerant now is R1234yf, which has replaced the previous R134a. The technician explained that R134a has a high global warming potential, exacerbating climate change, so it has been banned in many countries for use in new vehicles, necessitating the switch to the more environmentally friendly R1234yf. My old car used R134a, and while the cooling effect was decent, it didn't last long. After switching to the new refrigerant, the AC cools noticeably faster, making summer drives much more comfortable. The technician also mentioned that R1234yf decomposes more safely, with minimal environmental impact even if it leaks. For daily car maintenance, it's important to check the refrigerant level and system seals every two years to prevent leaks that could lead to insufficient cooling and energy waste. The shift in refrigerants is a trend pushing the automotive industry toward greater sustainability. Personally, I think timely repairs are the most cost-effective—saving money while protecting the environment. If the refrigerant level is low, the AC might make strange noises, so it's best to address it promptly.
