What Is a Semi-Hermetic Reciprocating Compressor?

The word “semi-hermetic” means the compressor or motor can be repaired, opened, or overhauled.

So semi-hermetic reciprocating compressor the reciprocating compressor where motor and compressor are housed together, both cooled by the refrigerant.

Though they are bolted together, they can be unbolted and removed from the panel to access their internal parts.

It is commonly known that semi-hermetic reciprocating compressors use cast iron casing the essential parts of the compressor.

It can be used in all high, medium, and low-temperature applications.

What Is the Advantage of a Semi-Hermetic Compressor?

There is no shell for an open compressor and a closed shell for the hermetic compressor in their construction types.

But the semi-hermetic compressor has a shell that can be opened, one of its best advantages.

The average noise level for other compressors is 85 DB(A), whereas the semi-hermetic reciprocating compressors generate 75 DB(A) noise.

So it’s less noise level, and less vibration level is another significant advantage. Some of its other advantages are:

• The leakage rate is lower,
• It can be opened effortlessly,
• The Motor temperature is low,
• The voltages selection range is wide,
• No route for gas to go out of the system,
• The replacement of inside components is easy,
• Any spare parts are available to repair and replace
• It consumes less power at the same horsepower as others,

What Is the Difference Between a Hermetic Compressor and A Semi?

In the hermetic compressor, the motor and compressor are located under one closed shell, which can’t open and be repaired because it is welded.

Still, the motor and compressor can be accessed after opening the shell in semi-hermetic.

When there is an impaired or abnormal function in the hermetic compressor, the full compressor needs to replace.

But for the semi-hermetic compressor’s motor or compressor and others, spare parts like valves can be repaired or replaced without replacing the full compressor unit.

As every part is sealed inside the shell, the hermetic compressor’s leakage rate is lower than semi-hermetic though it frequently happens for open types.

The hermetic compressor is common in domestic or residential air conditioning and refrigeration units.

On the other hand, the semi-hermetic reciprocating compressor is used in larger applications.

Such as commercial, industrial, supermarket, factory, plant, or other HVAC unit projects.

How Does a Semi-Hermetic Compressor Work?

When the motor of the semi-hermetic reciprocating compressor gets electricity.

It rotates the crankshaft of the compressor, which helps the piston to travel forth and back.

So while its stroke is made downward, it creates low-pressure rear in between the piston top and cylinder head.

Then the suction valve opens, and the gas flows into the low-pressure area.

When the piston is upstroke, the suction valve closes, leading the discharge valve to open because of high pressure.

Then the compressed gas is discharged by the force of high pressure.

This is how a semi-hermetic compressor raises the refrigerant gas’s temperature and distributes it by the proper piping system.

What Are Semi-Hermetic Compressors Used for?

Semi-hermetic reciprocating compressors are usually used in refrigeration systems, air conditioner systems, HVAC systems, etc.

The units matched with semi-hermetic reciprocating compressors are air-cooled units, water-cooled units, walk-in cooler condensing units, or central air conditioning units for air drying, cold rooms, mechanical industries, and other industrial applications.

Because of its efficiency, the semi-hermetic reciprocating compressor is also famous for commercial refrigeration units, cold room refrigeration units, or walk-in cooling units for different industries like pharmaceutical, chemical, electronics, and others.