View Single Post
  #246  
Old 03-20-2012, 02:09 PM
vstech's Avatar
vstech vstech is online now
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 27,026
Re: AC theory question
Haynes has a nice automotive a/c book, for learning the basics, and other methods, I recommend it.
as far as the charge goes, it's based on compressor volume capabilities, orifice or expansion valve flow characteristics, surface area of the coils along with its volumes, and airflow. it's a HIGHLY complicated formula to compute. which is why manufacturers always list refrigerant volumes on the vehicles.
you have enthalpy formulas along with P/T charts, and phase charts...
Quote:
Originally Posted by compu_85
John,

I have a question about AC systems in general: How do you figure out how much charge a system needs? IE say you just put together a whole system from scratch. Is it all based on temp / pressure charts? I saw one reference that said when the inlet and outlet of the evaporator are at the same temp it's correctly charged.

I'd love to learn more about this stuff... do you have any recommended reading?

Thanks,

-Jason
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Last edited by vstech; 03-26-2012 at 10:36 AM.
Reply With Quote