high temps cause higher low side preasure
If you have to add R22 to system because of a long run,this is not a long run,the pressure should still be around the 68-70 suction line shouldn't it?
If you are getting 16 to 20 difference comming out you are close very close..
You can not just set low side preasure to 68-70. That is a mistate. The preasure could be from 68-83 roughly. Depends on temp across the coil. high temps cause higher low side preasure. If you go to this house for example the air comming into the furnace is 80 degree and your low side preasure is 68 degrees you are low on preasure you need to add. if you have 80 degrees comming across the coil I would say your low side should read somewhare around 75 and 80.
Another way of checking to see if you are low on freon is to goto the furnace and listen to liquid line. If it sounds like its not enough freon comming through then its not.
Pratice listening to the liquid line.
[Edited by klyons20 on 06-13-2005 at 08:06 AM]