Are the line sets that come with the air conditioners PRE-CHARGED with refrigerant?
It is my understanding that the Line sets and Line set extensions are PRE-VACUUMED and do not have refrigerant in them.
The refrigerant is typically stored in the compressor/outdoor unit and is released into the system when installed.
One would need to pump down the refrigerant to the compressor or to a storage tank when moving or replacing the outdoor unit, otherwise one has to replace the refrigerant. Please clarify.