What are Scroll Compressors?

This is a great explanation of scroll compressors used in the air conditioner and heat pumps in our homes and offices:

The black cylinder with piping extending from it in your air conditioning unit is the scroll compressor. This component is responsible for compressing the refrigerant,

Scroll Compressors in Air Conditioning Equipment

generally R-22 or R-410, in air conditioning equipment. As the replacement for older piston type compressors, scroll compressors are able to provide the same amount of cooling with but in a smaller machine size.

Scroll compressors use one stationary threaded cylinder and a mating threaded scroll that encircles the stationary circle, trapping and displacing the refrigerant gas, from the initial suction until it discharges. The quick reduction of volume causes the compression and directs the flow of the refrigerant from the inlet opening to the outlet opening. The process transforms the kinetic energy into potential energy.

Compressors for air conditioning units are categorized in two ways. The first being seal type, which refers to sealed, semi-sealed, or open type. The second being operation type, and is based on whether the compressor is piston, centrifugal, rotary or scroll driven. The compressors are then tested and rated according to several factors including rotational speed, mass flow rate, pressure ratio, efficiency, and maximum pressure. Some of these tests are performed as comparison values between two of the factors.

The original version of the scroll compressor was invented in the early twentieth century. In the late 1960′s the compressor was upgraded to the type we see and use today. The benefit of scroll compressors is their ability to provide higher efficiency, the same flow rate and the same outlet pressure in a much smaller unit size compared to larger bulkier versions of piston and reciprocating type compressors.

The process used by scroll compressors is more complicated than piston type compressors due to the performance drop of the scroll compared to a much higher ratio then piston type. Now the use of scroll compressors is generally mandated in most air conditioning units because of its advantages over piston type compressors.

While scroll compressors provide advantages over other types, there are some drawbacks to its use. Since they do not have suction valves, they can have failures due to debris build up. The lack of radial and axial compliance operation, provide even more possible complications caused by foreign matter or debris.

To read the rest of this explanation at Scroll Compressors on Squidoo.