> Compressors

• Five most common types

– Reciprocating

• Uses a piston-cylinder and valves
• Most common type of compressor
• Use this type for your projects

– Screw

• Lobes of two rotating screws trap and compress gas

– Centrifugal

• Uses centrifugal force to compress gas
• Common in large systems (200 to 10000 kW of refrigeration

capacity)

– Vane

• Uses a roller to compress gas
• Used in most domestic refrigeration and ac systems

– Scroll

• Two inter-fitting spiral-shaped scrolls compress the gas
• Used in 115, ton(35 to 53kW)range, ac applications

 

> Terminology

• Open-type compressor

– Crankshaft extends through housing to connect with the

motor

– Seals are used to limit refrigerant leakage

• Hermetically sealed

– Motor and compressor are combined in the same housing

– Used for small domestic systems

 

• Semi-hermetic

– Cylinder heads are removable for serviceability. Good for

systems larger than domestic.

• Condensing unit

– Motor, compressor, and condenser are combined in one unit

and sold together