How Do Air Conditioners Work?

 

How Do Air Conditioners Cool?
Air conditioners utilize the evaporation and condensation properties of R22 or R410 gas to expel heat from the environment. In split air conditioners, the gas passing through the indoor unit absorbs the heat in the environment and evaporates. This process cools the environment. The evaporated R22 gas reaches the outdoor unit, where it condenses and releases the absorbed heat outside. During this process, only the fan motors in the indoor and outdoor units and the compressor circulating the gas consume electrical energy.

How Do Air Conditioners Heat?
Heat pump air conditioners, as the name suggests, use external heat to warm the environment instead of directly converting electrical energy into heat. These air conditioners perform heating through the condensation and evaporation of R22 gas, just as they do for cooling. For heating, the gas passing through the outdoor unit absorbs heat from the outside and releases it into the indoor environment upon condensation in the indoor unit.

The efficiency of air conditioners in heating or cooling depends on external and internal air temperatures. As the outdoor air temperature increases, the cooling performance decreases, and as it decreases, the heating performance declines. Heat pump air conditioners are particularly economical when the outdoor air temperature is around 7°C. For this reason, they are preferable in mild winters, spring, and autumn. The compressor absorbs heat from the evaporator, compresses it, and sends the high-pressure hot refrigerant gas to the condenser. The gas condenses into a liquid in the condenser. The expansion valve converts this liquid refrigerant into a low-temperature, low-pressure liquid-gas mixture. This low-temperature refrigerant enters the evaporator. As the liquid evaporates in the evaporator, it absorbs heat from the airflow passing through the evaporator fins. This process is repeated continuously.

Main Components in Cooling Cycle:

Compressors
Compressors are the heart of the system, compressing the refrigerant gas from low pressure and temperature to a higher pressure and temperature, enabling it to flow through the condenser. There are three main types:

• Reciprocating Compressors
  The most commonly used type, ranging from small single-cylinder models to large 16-cylinder ones.

• Rotary Compressors
  Quieter and more compact than reciprocating compressors, they consume less energy but are more prone to breakdowns and often irreparable. These compressors use rotational movement instead of pistons, commonly found in devices with low power requirements.

• Scroll Compressors
  These use a unique mechanism involving two interlocking spirals. One spiral remains stationary while the other moves in an orbital path, compressing the refrigerant. They are efficient, quiet, and compact but costly and non-repairable. Proper installation and protection mechanisms are essential to avoid damage.

Heat Pumps:

Heat pumps transfer heat from one environment to another, just like cooling machines. However, they can transfer heat in two directions. In addition to typical components like evaporators, condensers, compressors, and expansion valves, heat pumps include a four-way valve.
In winter, heat pumps absorb heat from outside and transfer it indoors, while the process reverses in summer.

Types of Heat Pumps:

• Air-to-Air Heat Pumps: Transfer heat between indoor and outdoor air, commonly seen in window and split air conditioners.
• Air-to-Water Heat Pumps: Use air as a heat source in winter and water in summer for heat transfer.
• Water-to-Water Heat Pumps: Designed to use water sources such as wells, lakes, or rivers for heating and cooling.
• Air-to-Ground Heat Pumps: Similar to air-to-water systems but use the ground as the heat source or absorber.

These applications are less common compared to other types.