Air conditioning systems are complex machines that use a variety of components to cool the air in a room or building. Understanding the four main components of an air conditioner is essential for proper installation and maintenance of the system. The four components are the evaporator, compressor, condenser, and expansion valve.
The Evaporator
The evaporator is the inner part of the system, known as the “cold side”, and contains a fan that blows air over cooled coils and into the room.This is where the cooling process begins when a thermostat detects that it is necessary to lower the air temperature and sends signals to components inside and outside the house to start working. As liquid refrigerant inside the evaporator coil is converted to gas, heat from indoor air is absorbed into the refrigerant, cooling it as it passes over the coil.
The Compressor
The compressor is an electric pump that pressurizes the refrigerant gas as part of the process of converting it back into liquid. It is located on the hot side of the system and works together with the condenser and another fan to vent hot air from the compressed refrigerant to the outside.The CondenserThe condenser is located on the hot side of the system and works together with the compressor and another fan to vent hot air from the compressed refrigerant to the outside. It helps absorb heat from inside and release it outside.
The Expansion Valve
The expansion valve regulates the amount of compressed liquid refrigerant entering the evaporator. Once in the evaporator, it experiences a pressure drop, expands and turns back into gas.Types of Air ConditionersWindow air conditioners are a common option for controlling temperature in a small room. They contain all four components in one unit and are designed to fit on a window. Wall units are similar but require a hole in the wall for installation. Central air conditioning systems are used to cool large spaces and consist of two parts: an outdoor unit containing a compressor, condenser, coils, and fan; and an indoor unit containing an evaporator and expansion valve.
Multi-split systems offer multiple indoor units operating from one outdoor unit. A large fan draws outside air through the condenser coil, allowing it to absorb heat from inside and release it outside. Local air conditioning systems serve an area without crossing boundaries. Evaporative coolers work best in dry climates and use a fan to draw outside air through moistened pads, cooling it as it passes through.
Packaged terminal air conditioners (PTACs) are similar to window units but are designed for commercial use. They can be adapted to provide heating in cold climates by reversing the flow of coolant or using an electrical strip, gas or other heaters. The split design keeps noisy components outside, making them ideal for sleeping areas or spaces where minimum sound levels are important. Air conditioning is part of a family of systems and techniques that provide heating, ventilation and air conditioning (HVAC).
Knowing which type of system is best suited for your needs will help you make an informed decision when selecting an air conditioner. Understanding how each component works together is essential for proper installation and maintenance of an air conditioning system.
