Evacuation Levels Prior To Refrigerant Charge
Evacuation Levels Prior To Refrigerant Charge
(OP)
Any air conditioner manufacturing engineers out there? What micron level do you evacuate your units to prior to refrigerant charge in order to "boil off" the moisture? We've polled many of our clients and would like to broaden the scope of our research for our VacuCharge system:
http://www.ecicomplete.com/vacucharge.html
So far it appears that the average is 200-400 microns.
http://www.ecicomplete.com/vacucharge.html
So far it appears that the average is 200-400 microns.





RE: Evacuation Levels Prior To Refrigerant Charge
I'm interfering in there tests so I know foe a fact it's going to be a warrantee issue in a little while.
RE: Evacuation Levels Prior To Refrigerant Charge
It is preferred to take the vacuum reading from an access directly into the system, as far from the pump's connection as possible.
Age old battle, as noted by hockeyman. Engineering wants the lowest vacuum possible. Production wants a much higher level.
Minimum pressure reached is not the only thing to consider. Time at that level with the pump connected and running is also important. Vacuum decay with the pump isolated from the system can indicate either a leak or condensible gasses making their way out of the oil.
300 microns of mercury for at least an hour would be the minimum that I would accept for something I was buying.
RE: Evacuation Levels Prior To Refrigerant Charge
1st evacuation
break vacuum with dry nitrogen
2nd evacuation
break vacuum with dry nitrogen
3rd evacuation to 500 microns
By introducing dry nitrogen into an evacuated system a couple of times you help to "blot up" residual moisture. Dry nitrogen is capable of absorbing a small quantity of moisture. You might consider the habit of introducing nitrogen just through the high side (especially when in the nitrogen pressure testing process) That way you can see if there is high side to low side flow. If you determine that there is a restriction, it will be easier to rectify the situation now rather than later when you try charging the system.
RE: Evacuation Levels Prior To Refrigerant Charge