a/c questions

[bigchillcar]

One misconception is that the Sanden is a rotary compressor. It isn't -- it's a wobble-plate/piston configuration.

true....observe...
ryan

[bigchillcar]

here's dyneco corporation's sectional view of their orbital vane rotary compressor:
ryan

[911pcars]

I only mentioned the Sanden in relative terms. It was more efficient than the old York compressor used in early 911 A/C applications. Not sure who has the most efficient compressor on the market.

Nippon Denso makes a good product. They supply OEM pieces (compressors, starters, alternators, HVAC pieces, etc.) to a number of car companies including MB, Toyota and Porsche (I think).

One current ND compressor is a variable displacement type that uses a swash plate (or wobble plate) configuration. A control valve (ECU-operated) monitors A/C system pressure and, if cooling requirements change, reduces the displacement by straightening the swash plate (less angle, less piston displacement). This is supposed to increase system efficiency. Newer systems also use only a fraction of the refrigerant older systems used.

FWIW, Hybrid cars, because of the nature of their gas engine (ON, then OFF, then ON, etc.) use an electric A/C compressor, otherwise the interior air temperature would fluctuate wildly using a regular belt-drive compressor. You can sit with the "engine" OFF and still have cool air circulating around your hot spots. Cool (pun).

On a related note, Howard Hughes converted a Buick's A/C into an electric system to satisfy his penchant for sanitary microbes (no doubt for auditioning Hollywood beauties while stationary). That same car was purchased last year at a BJ auction for a cool 1+ million. If those seats could talk .......

Sherwood