That unit would be considered light commercial and like any other piece of equipment life expectancy depends on maintenance performed and that unit appears to be lacking.
You Should have a Delta T across the water loop just like on a any other system. Any reputable installed unit would have pressure gages and thermometers in the water loop supply and return. I would recommend checking the intake side of the condenser for Matting thought I could see 3 condenser fan brackets means you are moving a large volume of air across the condenser very easy to block.
Your Evap would be like a hot water heater lying on its side and should be insulated water header would probally be on one end and the freon header with expansion valve would probally be located on the other end.