Even without being an expert in cars, you know very well that AC systems are responsible for cooling the air that moves inside the ride. The process goes in a very comprehensible manner. It starts by blowing air that enters the car over the evaporator or cooled surface. From there, the heat present in the air is transferred to the coolant then flows through the unit. This simple principle will somehow make you wonder what else makes your Volvo A/C system work. The following parts in the system are responsible for that.
The refrigerant is responsible in cooling the system. It has the capability to change physical properties once it gets compressed, metered, and cooled in the compressor. Back then, before 1994, the most common type of refrigerant used in an AC system is the R12. Use of such was discontinued because this type of refrigerant is highly polluting by nature. This is why the most commonly used refrigerant these days have been changed to R134A or Freon.
One of the most important parts that make the A/C system work is the compressor. This is considered as the life of the entire system. It is where the refrigerant gas is compressed. Once the refrigerant is compressed through this part, it turns into a hot temperature which will then be sent into the condenser.
From the hot gas that has been compressed via the compressor, the condenser will then work to remove the heat from the gas. This is a series of coils where outside air passes through to help in condensing and eventually cooling the liquid. It comes in different types. One is the serpentine-style condenser which can be flushed in case it fails. The other is the parallel style which cannot be flushed and will need immediate replacement once it malfunctions.
This is the canister where the desiccant can be found. The desiccant is responsible in absorbing moisture in the system. Many of the receiver-dryers that you see today come with a glass on top where you can observe how the refrigerant flows. In the case of retrofitted systems, the slight-glass type is useless since the oil being used with that of the Freon is non-transparent.
This is where the refrigerant flow is restricted in order to allow the liquid to change from a high pressure to a low pressure one. The mist created by the low-pressure liquid will then enter into the evaporator. Once the expansion valve fails, you can take that as a sign that something has clogged the device. It works the same way as the orifice tube does.
It is where the low pressure mist from the expansion valve flows. When this happens, the blower motor does its job of pushing the air across the evaporator's cold tubes. This is responsible in delivering the cooled air into the cabin or passenger compartment of the vehicle.
This looks like a holding tank where the refrigerant takes time to exit from the evaporator. As the refrigerant circulates inside the accumulator, the desiccant bag inside it will remove the moisture that is present in the system.