Refrigerators do use freon. If it was manufactured before (around) 1995, it probably has R-12 refrigerant. If it was manufactured after 1995, it most likely has R-134a refrigerant. R-12 refrigerant has better cooling properties than R-135a, but is known to hurt the environment (and supposedly create mustard-gas if rapidly heated), so R-12 is no longer available. If there isn't a leak in the refrigeration system, I doubt that you would need it to be recharged. I'm not sure how familiar you are with refrigeration, so I'll play it out as dumb (no offence). A refrigeration system transfers heat from one location (inside) to another location (outside). The cooling coils on the inside (the evaporator) will absorb the warmth from the inside of the refrigerator by using the freon in the lines, and that heat is transferred through the freon to the outside coils (the condenser) of the refrigerator, where the heat is dissipated out to the atmosphere. If there is a blockage, either preventing the air inside the refrigerator from being absorbed or preventing the heat from dissipating off from the outside coils, the refrigerator will not cool sufficiently, because there is no means of heat transfer. Ambient temperature plays a significant role in cooling as well. If it is 100+ degrees outside of the refrigerator, the heat from the condenser will not be able to properly cool, so the heat from the inside of the refrigerator (which is now in the condenser on the outside) will get circulated back into the inside of the refrigerator. A faulty thermostat can also be of concern. If the thermostat thinks that 50 degrees is actually 35 degrees, then the thermostat will turn of the compressor (which circulates the freon) when it reaches 50 degrees, because it thinks it's at 35 degrees. There may be also something wrong "pressure differential" unit inside the refrigeration lines. I say "pressure differential", because there are several different setups here. If that "pressure differential" unit is not allowing a for a restriction in the refrigeration lines, then the freon will just cycle through the lines without doing anything.