Hey guys! Sorry for not updating for a long time. I wanted to upload, but couldn’t upload due to academic commitments. Just college stuff, to simply put it. Now, you must be wondering, how do you stay cool in your car even in the intense Bombay heat, and stay warm in your car in the intense winters of Kashmir? How does the heater and air-conditioner in your car work? Let’s find out.
So, to start off, the A/C in your car uses a liquid stored in a pressurized, air-tight can, which is called a refrigerant. The refrigerant in your modern car consists of Hydrochlorofluorocarbons(H-CFC). We used to use Freon, when refrigeration was discovered in the early 1900s, but the process produced harmful gases which could kill someone, so they were removed. We used to use CFC’s till quite recently. However, they are not used because they contribute to global warming. The environment needs to be taken into consideration, it’s the 21st Century after all! To be specific, in modern cars today, the refrigerant R-134-a is used in your car’s A/C, which is a HCFC (hydrochlorofluorocarbon). The compressor, compresses this refrigerant, and thus increases its temperature and pressure. The compressed gas passes through the condenser, which is placed near the radiator of the car. The condenser, uses outside air to cool down the compressed gas, and bring the gas to liquid state, or in other words, condenses it. The refrigerant then passes through the receiver-drier, which removes moisture and filters out solid particles, making the air dry and not humid. Then, the refrigerant enters the expansion valve, where its pressure is reduced. The refrigerant then enters the evaporator as a liquid, where it evaporates due to heat from the car’s engine, and the evaporator, which is connected to a fan, and cabin air filter, and through these two it is connected to the passenger cabin through vents, and since evaporation of refrigerant makes the air cooler, the A/C cools the cabin, and the cycle repeats itself and goes on to keep the cabin cool. Thus, a car’s air-conditioner works by changing the state of refrigerant between a liquid and a gas, which absorbs heat and humidity from the air inside the car. Now, you might be asking, is it unkillable? No. You will lose cooling as time passes, which means that the car is out of refrigerant. So, when you go for a service, you ensure that the A/C is cool by filling up refrigerant regularly, and cleaning the cabin air filter, which ensures that dust and other impurities don’t get into the cabin. By the way, failure of any of these components might mean that you’re A/C won’t cool the cabin properly. Now, you might also be asking-Why does the A/C put load on the car’s engine? It’s because the compressor that we mentioned is driven by the engine, consuming more fuel, and making the engine’s job harder. Also, because the refrigerant has to be cooled, the A/C system needs to exchange heat with the outside environment, which puts more load on the engine.
Now, how does the heater work? It transfers heat directly from the car’s engine to the cabin. Surprised? I know! Right? It’s that simple! It takes heat from the car’s engine, which is a great heat source! That’s the logic behind an old trick that your parents might know. Whenever the engine of your car overheats, you put the heater on full blast, and open all the windows of your car fully. This directs heat away from the car’s engine and might get you there safely, after which you can look into the cause for the engine overheating. So, the car’s heater works by transferring heat from the car’s radiator, to the heater core, heater control valve, and the same fan that blows all that hot air into the cabin.
