Does it really matter that much?
If so why?
Reciprocating compressors are a mature product. They'll last just as long as a scroll. More importantly they've been around long enough to prove it.
Scrolls can finally be called mature. They have distinct advantages that I won't get into because the overall advantage is nil in my opinion. If both can last a couple decades or more then what does it matter which you buy? But then again... Scrolls will supposedly take abuse better. So if you plan on running the AC in winter and never changing the filter then scroll is the only way to go.
In terms of energy efficiency, as far as the end buyer is concerned it's the entire condensing unit that's rated for a certain efficiency - not the compressor. Scrolls may have some negligible advantages in terms of energy efficiency. But a 13 SEER air conditioner is a 13 SEER air conditioner regardless of the compressor that's in it.
In other words, IF this has to do with a buying decision then your focus is skewed. The quality of the contractor is ten times more important (Check out the wall of shame forum.). He builds your system. The OEM just supplies parts. If you've gotten a few bids you'll be lucky if even one of them plans on doing everything that needs to be done.
Mainly, scrolls are quieter. I believe there are fewer failures with scrolls as well. They are also more efficient,to the manufacturer, whom can install a smaller compressor to do the same job.
never say never
i was also told that a scroll will not wear out like a piston cylinder would. when the scroll came out they said over time it would actually wear in to become more efficient.
Scrolls are more efficient because they have 0 clearance volume.
Translation= When a piston reaches the top of the stroke there is space left between the head and the piston so that it won't damage the valves (clearance volume). When the piston starts traveling on it's downstroke, the higer pressure gas in this space must re-expand and drop the pressure to below that of the gas waiting to enter behind the suction valve and the spring tension of the valve itself before any gas will enter.
So with a reciprocating compressor only a portion of the full stroke of the piston is utilized.
Every bit of refrigerant that goes into a scroll comes out through the discharge.
Scrolls aren't bulletproof but most guys will tell you that you will see fewer scrolls than recips in the warehouse returns area.
The scroll sure is a lot more forgiving when the old filter or evap. get dirty and you start sending some liquid back to the old pump.
Experience is a hard teacher because she gives the test first, the lesson afterwards". -Vernon Law-
"Skilled Labor Isn't Cheap, Cheap Labor Isn't Skilled" - Unknown