How refrigerant actually works
Refrigerant circulates in a sealed loop, absorbing heat indoors and releasing it outdoors. It changes state between liquid and vapor but is never used up. That single fact explains why 'the system needs refrigerant every year' is a description of an unrepaired leak, not routine maintenance.
Charge level matters precisely. Too little and the coil runs cold enough to freeze while cooling capacity collapses. Too much and head pressure rises and the compressor suffers. This is why charge is measured and weighed rather than estimated.
Signs of a leak
- Cooling that has gradually declined over weeks rather than failing overnight
- Ice on the indoor coil or the suction line
- Longer and longer run times with rising electricity use
- A hissing or bubbling sound near the indoor unit or line set
- Oil residue near fittings, service valves or the coil
- Cooling that improved right after a previous 'top-off' and then declined again
Where leaks usually occur
- Evaporator coil tubing, especially formicary corrosion on older coils
- Condenser coil damage from impact or landscaping equipment
- Brazed joints and flare fittings in the line set
- Schrader valve cores at the service ports
- Vibration-worn contact points where tubing rubs a cabinet edge
Why 'just add refrigerant' is a bad deal
Adding refrigerant to a leaking system buys temporary comfort at real cost. The refrigerant leaves again, the compressor keeps operating outside its design envelope, and the money spent produces no lasting result. Some refrigerant types have also become significantly more expensive, which makes repeat recharges an expensive habit.
If a provider proposes a recharge, it is fair to ask: was a leak search performed, where is the leak, and what is the plan to repair it?
What proper leak repair involves
- Electronic leak detection, bubble solution, UV dye or nitrogen pressure testing to locate the source
- Recovery of the remaining refrigerant using approved equipment
- Repair or component replacement at the leak point
- Deep vacuum to remove moisture and non-condensables
- Weighed-in charge to the manufacturer's specification, then performance verification
Cost drivers
Accessibility is the biggest variable. A leaking Schrader core is inexpensive. A leaking evaporator coil buried in an attic air handler is not, because the coil usually must be replaced and the labor is significant. Refrigerant type and required quantity also matter, and older systems using phased-down refrigerants can be expensive to recharge.
When the estimated repair approaches a substantial share of replacement cost on aging equipment, it is reasonable to price both options before deciding.
Safety note
Refrigerant handling is regulated and requires certification and recovery equipment. Do not use retail sealant products or DIY recharge kits sold for automotive use — they can contaminate the system, damage service equipment and make future repairs more expensive or impossible.