Originally Posted by
Rob White
.
Looking at your first post and the last one, if I understand you
correctly, the test is referring to oil return back to the compressor
via the suction line.
Mass flow rates of the refrigerant will affect the oil return so that
is why the test is done at minimum flow rates (mass flow).
If the evaporator is below the compressor then traps in the suction
will be required. The size of the pipe is a factor as well.
So if it is a reversible heat pump the oil passing round the system
will have to be calculated and that will mean the oil return must be
in heating and cooling mode.
Rob
.