Refrigerant, commonly referred to as Freon, is pumped through the system by the compressor. The compressor does not “use” refrigerant, it just pumps it. The refrigerant system is a sealed system. If your system’s refrigerant levels are low, it is because refrigerant is leaking from the system. Whenever we find a system that is not cooling properly due to low refrigerant levels, we perform an electronic leak search to locate the source of the leak. We then inform you what is required to eliminate the leak. This can range anywhere from tightening a loose fitting to replacing a leaky coil. If the leak is small, the refrigerant can be topped off to restore cooling, but without repairing the leak, the refrigerant will leak out again. This sometimes can provide adequate cooling for a year, but eventually it will leak back out and the system will quit cooling. At one time, low refrigerant prices resulted in people choosing to top their system off every spring instead of paying for costly repairs, but as prices of refrigerant rise, this practice is becoming less common.