Refrigerant Leak Testing
Because HFC-134a is above atmospheric pressure at room te mperature, leak te sting can be
performed with refrig erant in the machine. Us e an el ectronic detector , soap bubble solution, or
ultra-sonic leak detector. Be su re that the room i s well ventil ated and free fro m concentration o f
refrigerant to keep false readings to a minimum. Before making any necessary repairs to a leak,
transfer all refrigera nt from the leaking ves s el .
Leak Rate
ASHRAE recommends that machines should be imm ed iately taken off line an d repaired if
the refrigerant lea kage rate for th e entire machine is more than 10% o f the operating re frigerant
charge per year.
Additionally, Carrie r recommends that leaks t otalling less than t he ab ove rate but more than
a rate of 1 lb (0.5 kg) per year sh oul d be repaired during an nual maintenance or whe never the
refrigerant is pumped ov e r for other service wo r k .
Test After Service, Repair, or Major Leak
If all refrigerant has been lo st or if the machine has bee n open ed for service, the machi ne or
the affected vessels must be pressured and leak t ested. Refer to the Leak Test Machine section
to perform a leak test.