Selection of compressor for AC recovery machine

Hi,

I am in a project of designing an AC recovery machine for automobile service stations and for that i need to select a hermetic compressor. The refrigerant used is R134a. As far i have analysed the competitor products most of them have used 12cc, 1/3 HP. I want to know how everyone have selected that specification. Is there any formulas to decide the cc of the compressor? And also from my analysis i have found minimum size of the ac system in a car is 370grams and maximum is about 1.15grams. So i want to select a compressor which shld satisfy that range. Please do suggest me how to proceed further...

Regards
Vijay

Why hermetic compressor?
For recovery machine you need oil-less compressor with compression ratio of 1:60.
Ordinary refrigeration compressor is not designed for that purpose. Its compression ratio is usually 1:5.

http://www.designnews.com/article/22...t_recovery.php

I think that if you are researching this subject you should begin with buying some competitor models so that you can replicate them properly.

Some more knowledge of the subject matter is needed also I think, it is not just a mechanical item, that you are trying to build; it has variable fluids going through it which need careful handling.

Hi Brain,

I have already decided to buy a competitor model but I want to justify why I am choosing 12cc compressor.

Reg
Vijay