A hermetic compressor is a tightly sealed compressor welded in a casing, enclosing all its essential components, including the motor and compressor itself, in that single outer welded casing.
When the motor shaft turns, it drives a piston inside the cylinder, and low-pressure gas from the evaporator drives into the compressor shell to cool the motor and lubricate oil.
Then, it enters the cylinder, gets compressed, and exits as a high-pressure refrigerant.
Application of Hermetic Compressors
It’s also used in home & deep freezers, commercial refrigerators, restaurant freezers, commercial refrigeration units, commercial outdoor units, heat pumps, split ACs, cold rooms, indoor condensing units, etc.
The types of hermetic compressors are the same as those of compressors based on working principle.
In that case, it’s not available for monitoring or repair.
Air conditioner unit: LG, Midea.
Advantages of Hermetic Compressors
The hermetic compressor’s design simplifies the mechanical connections and effectively reduces the risk of refrigerant leakage at the motor shaft.
So it can prevent the ingress of external contaminants like dust and moisture.
It reduces motion-induced vibration as the motor is mounted on the springs, which makes it less noisy.
The compact and lightweight design allows it to be best fit in applications like residential uses where the space is limited.
But because you can’t open it for maintenance, any failures cannot be fixed, even if it’s a minor issue.
So, to prevent system breakdown because of a single compressor unit failure, multiple compressors are chained together parallelly in a rack to achieve adequate working efficiency in some applications.