Question on suction line configuration. I suggest having a trap on the suction line AT the attic evaporator (air handler). The condensing unit is outside (of course) and about 20 feet below the air handler. Seems like a good idea not having all the refrigerant oil drain back to the compressor and making for a hard start. Trapping at the evaporator should hold some oil there, right? Or not worth it at all? Residential installation, 3 ton split.