How does compressed refrigeration or air conditioning work? / How do air conditioners work?
Air conditioners work mainly using four parts that oversee cooling and moving air inside and outside a room:
- Evaporator – Receives coolant
- Condenser – Allows heat transfer
- Expansion valve – Regulates how coolant flows within the evaporator
- Compressor – It’s a pump that pressurizes the coolant
The motor is on the outside of the unit, and it’s used to compress gas, becoming a liquid and increasing its temperature. This liquid is pushed towards the condenser located on the outside of the unit When it arrives to the condenser, a process known as sub-cooling begins where the gas steals heat from the condenser to become a mixture of gaseous and liquid gas that arrives to the expansion valve. This is where there is a loss of charge in the coolant, leading to a drop in pressure and gas temperature. Once this loss of charge happens, the gas moves to the evaporator located in the interior of the air conditioner, its function is to warm the gas (overheating). The gas has a lower temperature than the air in the room, which then goes to the evaporator, causing it to cool down and at the same time steal heat from the gas coolant, achieving a colder room.
Once the room’s warmth has been stolen with gas, it’s absorbed by the compressor, where it's cooled again since the gas that’s coming back is still cold. This process repeats numerous times until the room achieves the desired temperature. Once this temperature is achieved, the air conditioner thermostat will make the machine stop until the temperature starts to rise again, to repeat the process.
This cooling method has a starting high investment cost and operational cost because the compressor and other components require high electric currents. Also, this type of cooling uses recirculated air that in some cases may trap smells and smoke.