What is refrigerant?

Refrigerant is the working fluid inside an air conditioner. It moves through a sealed loop of copper pipe, linking the indoor evaporator coil in the living room or bedroom to the outdoor condenser unit mounted on the balcony, yard, or rooftop. Along the way it picks up heat from the indoor air and drops it outside.

The fluid does this by changing state. At the indoor coil, low-pressure refrigerant evaporates into a gas, pulling heat from the air blowing across the fins. The compressor then squeezes that gas, raising its temperature and pressure. At the outdoor coil, the hot gas gives up its heat to the outside air and condenses back into a liquid, ready to repeat the loop through the expansion valve.

Refrigerant matters because the whole cooling effect depends on it. If the charge is low, the system cannot move enough heat, so the room stays warm and the compressor can overheat. A leak is the usual reason a unit stops cooling properly, which is why technicians check pressures and top up or repair the circuit rather than simply adding fluid without finding the source.

Different refrigerant types are used in different equipment, and each has its own pressure range and handling rules. Older units in Singapore commonly used R22, while newer split systems mostly use R32 or R410A. Only trained technicians should open a sealed refrigerant circuit, and the fluid must be recovered rather than vented.

If you need someone to check or recharge refrigerant in a unit, you can find local providers in the aircon repair category.