1) the power rating of a refrigeration compressor;
2) a volume of water you want to cool;
3) the temperature lowering you want for the water.
Then you ask what to look for.
Answer: You are asking for something no one can respond to with certainty. You've given a quantity - not a rate. This is not a question of language; it's a question of logic. You either have a Batch process or a steady-state process. If you have a Batch process (a quantity of water is involved), then you have to state the time constraint (the time to cool down the given batch).
If you have a steady-state process (like most industrial refrigeration processes), then you must state the rate of the heat load you are imposing on the refrigeration process.
All you need to do is make a heat and material balance around the refrigeration system, and calculate the displacement of the refrigeration compressor with respect to the stated power rating.
