Hi guys a quickie on a/c,

My boss just got me to endo flush an old system because the indoor/outdoor units are being replaced but keeping majority of the pipework to save on instalation time, but now the new unit has arrived the suction line is spec at 5/8" but the exiting pipework already installed is 3/4". The liquid line is the same 3/8".

He says this is o.k as the refrigerant will have less resistance in the suction line thus making it more efficiant.

is this the case? and if so, as the unit has a reversing valve what will happen when the sytem is heating? will the suction line now the hot gas line not be reduced in pressure causing lower temps thus lower heating efficiency.

plz tell me more is my boss being a cowboy or is he correct?