A/C charging

don_160

you get to the bar,promise me you're not going to act the fool and botted up.

Does that help?

Barrington White

A/C charging

In class I believe you taught us when charging a system you should charge a system from the high and low side(but start with the low side). My experience from working out in the field was that my superior told me it was proper to charge from the low side. I think his reasoning was that the refrigerant should go directly to the compressor so it does'nt get bottled up in the system.

michael terry

high

pressure goes to low pressure always. you really dont have much of a choice if the system already has freon in it.the pressure in the refrigerant jug has to be higher than the low side pressure or it will not flow.the only time this can be a problem is when you live in a cooler climate and you are dealing with heat pumps that might be low on charge. and you left your freon out in the van all night and it got really cold.but anyway if you are dealing with a system that has just been evacuated you can put liquid freon into the high side using a set of scales you can get most of if not all of the factory specified charge into the system.remember when charging into the low side that you have to be careful as a rule it is a vapor only situation but this is not always practical. if you are not familiar with charging your best bet would be to go out in the field with someone who is and get some hands on training .to often adding freon is every techs answer to complaints of poor performance.its easier for them to grab the gauges and jug than to get the water hose or craw into the scary spider infested crawspace to see how dirty the evap coil is. hope that I helped you good luck
mike terry

Eugene Silberstein 3

Not Quite Barrington

When you have a system that is completely void of refrigerant and properly evacuated, refrigerant can initially be added to the system from wither the high or low side. This also depends on whether or not you are putting in a holding charge for future start-up or if you are planning on starting the system up immediately.

For immediate startup, you should add liquid to the high side of the system and allow the refrigerant to flow through the system to the low side, where it will vaporize after passing through the metering device.

On systems that are already in operation, adding refrigerant through the high side is a difficult trick at best. Since high pressure goes to low pressure and low side pressure had better be lower than the high side pressure, adding VAPOR refrigerant to the system through the low side is the preferred method.

Of course, if you are dealing with blended refrigerants that have large temperature glides and tend to fractionate, the refrigerant must leave the tank as a liquid, so be sure to charge carefully and slowly to avoid having the liquid flood back to the compressor.

So, Barrington, the reason for charging through the low side is more of a matter of physics, than to prevent refrigerant from getting "bottled up" in the system as you put it. Maybe a definition of "bottled up" would prove useful"?

Eugene Silberstein 3

Thanks, Don