A/C frozen Suction line
Frozen suction line and evaporator coils can be caused by a few different items.  But basically the A/C unit is making more cooling than the air flow can dissipate. Dirty filters is the first place to look.  They will restrict air flow.  Not enough air flow means inability to dissipate cooling to the room, means freeze-up. If the filters are good, look at the coil itself.  Is it dirty?  Shut the system down, defrost the coil then you can inspect it.  If it is dirty, you have to clean it.  dirt on the coil face will restrict air flow.  Lack of air flow can mean freeze-up. Now check to make sure the blower wheel is clean.  A dirty blower wheel cannot mover air like it should.  If it is dirty, you have to pull that blower wheel and clean it.  Not very much dirt on those fins can reduce the efficiency of the wheel a lot.  Not enough air movement across the coil means freezing. Now think about it this way, you want to direct as much warm air across those coils as you possibly can.  Is there any way to augment the flow of the warm air in the room across those cooling coils? If the room thermostat is calling for cooling those compressors are going to run.  When they run they are going to produce a certain amount of cooling regardless of other conditions in the room.  If you can't dissipate that cooling off the coils they will over cool and freeze.  With a frozen coil, not enough air flow across the coil is 95% of the time the problem.  Either move more air or shut the units for a short period of time to let the warm air catch up.  This is a good start. Good Luck.