3.2. Cycle Steps

The compressor pressurizes refrigerant gas, increasing its temperature and pressure.

The compressor is a crucial component of the air conditioning cycle. When the system is turned on, the compressor takes in the refrigerant gas from the evaporator. It works by compressing this gas, which raises both its temperature and pressure. The reason this happens is that when gas is compressed, its molecules are pushed closer together, leading to an increase in both temperature and pressure.

Think of a bicycle pump. When you push down on the pump, you compress the air inside, making it warm and pushing it into the tire at high pressure. Similarly, the compressor increases the pressure and heat of the refrigerant gas.

Compressed refrigerant moves to the condenser, where it releases heat and changes to a liquid.

After being compressed, the hot, high-pressure refrigerant gas flows into the condenser. Here, it releases heat to the outside air. The condenser has fins or coils that allow air to flow over it, cooling the refrigerant down. As it cools, the refrigerant changes from a gas to a liquid. This phase change is crucial as it enables the refrigerant to take on a liquid form that can easily flow through the next steps in the cycle.

Imagine boiling water. As the steam (gas) rises and cools in the air, it condenses back into droplets of water (liquid) on a cold surface. The refrigerant gas loses heat in the condenser just like steam loses heat as it cools.

This liquid travels through a filter/drier to remove moisture and impurities.

Before the liquid refrigerant moves to the next phase, it passes through a filter or drier. This component is essential because any moisture or impurities in the refrigerant can affect the performance of the air conditioning system and can lead to corrosion or damage. The filter removes these contaminants, ensuring that only clean, dry liquid refrigerant continues through the cycle.

Think of a coffee filter; just as it removes grounds from the coffee, allowing only liquid to pass through, the filter/drier in the air conditioning system ensures that only pure refrigerant flows to the expansion valve.

The expansion valve or orifice tube causes a rapid pressure drop, partially vaporizing the refrigerant and lowering its temperature.

As the liquid refrigerant leaves the filter, it flows into the expansion valve or orifice tube. This component allows the refrigerant to expand, which results in a rapid drop in pressure. When the pressure drops, the temperature of the refrigerant also falls. This cooling effect prepares the refrigerant for its next role in the evaporator, where it will absorb heat.

Think of a can of soda. When you open that can, the pressure inside drops suddenly, and you can feel the cold air rush out. Similarly, when the refrigerant expands, it cools down quickly.

Cold refrigerant enters the evaporator; air blown across the evaporator fin surfaces becomes cold and dry and is directed into the cabin.

The cold refrigerant flows into the evaporator, where it absorbs heat from the cabin air. As the blower pushes air across the evaporator fins, the refrigerant inside the fins absorbs heat from this air, turning the refrigerant from a liquid back into a gas. This heat absorption results in cold air, which is then circulated into the vehicle cabin, making it cool and comfortable.

Imagine standing in front of a fan with ice. As the warm air from your body passes over the ice, it cools down before reaching you. The evaporator functions the same way, absorbing heat and sending cool air into the cabin.

Heated refrigerant vapor returns to the compressor, and the cycle repeats.

After the refrigerant has absorbed heat from the cabin air and has turned back into a gas, it flows back to the compressor. This marks the completion of one full cycle and the beginning of another. The whole process is continuous, allowing the air conditioning system to maintain a steady flow of cool air into the cabin as long as the system is operational.

Think of a carousel at a fair. Once it completes a rotation, it starts back again from the beginning. The air conditioning cycle is like that, continually circulating and refreshing the cabin air.

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