The formation of a puddle of water under the refrigeration unit is a very common problem. In figure 85, note that the suction line going into the compressor runs next to the capillary tube coming from the filter-drier and condenser. When the warm capillary tube is placed next to the cold suction line, its heat is transferred to the suction line. This causes the capillary tube to become cooler, and the suction-line temperature to rise at the same time.
The purpose of this heat exchanger is to help the capillary tube start cooling down on its way to the evaporator, and to help the suction line to warm up on its way to the compressor. Usually, in residential and light commercial units, these two lines are brazed together at the factory or placed together and insulated on the assembly line to form a permanent heat exchanger.
The suction line coming from the evaporator is cold; when it is not insulated, it causes condensation when
coming in contact with surrounding warmer air. This moisture drips on the floor. If water is found on the floor, inspect the heat exchanger. More than likely the insulation is damaged or unwrapped. Put these two lines together and bind them with an insulation such as duct tape, and the condensation will stop.
In commercial refrigeration and air-conditioning units, the suction line is covered with a heavy sleeve for insulation to prevent condensation.