chiller problems

[Achilles1882]

my 1/3 hp chiller is freezing up... it has plenty of air flow and you can see where the lines are freezing up. Is the problem not enough flow or is it that it is low on freon and need a recharge? The main line from the reservoir freezes first and then the return line then begins to freeze If left overnight then both lines and the heat exchanger freeze up.

Thanks in advance,

Thomas