The 'indoor half' of your AC
The evaporator coil is the indoor component where the actual cooling happens. Liquid refrigerant expands inside the coil, absorbs heat from your home's air as it evaporates, and the blower pushes that now-cool air through the ducts. If the evaporator isn't doing its job, your compressor is working hard and your home isn't getting cold.
Freezing is the #1 sign of trouble
A frozen evaporator — ice building up on the coil or the suction line — almost always means low airflow or low refrigerant. Houston's humid air makes the freeze-thaw-freeze cycle worse: the coil ices, melts, and the resulting water overwhelms the drain. Solving it means fixing the airflow or finding the refrigerant leak, not just chipping off the ice.
The pinhole-leak problem in humid climates
Houston air carries volatile compounds from the petrochemical coast that, combined with constant moisture, slowly corrode copper coils. The result is formicary corrosion — tiny pinhole leaks that bleed refrigerant over months. A coil that's a few years old and leaking like this is more economical to replace than to keep patching.
Repair vs. replace the coil
A coil replacement runs a few thousand dollars but restores efficiency and often carries a new warranty. The decision comes down to the system's age, refrigerant type, and the coil's condition. On an R-22 system past 10 years old, replacing just the coil usually isn't smart money — the whole system is due.
Frequently Asked Questions
How do I know if my evaporator coil is bad?
Signs include ice building on the coil or suction line, weak cooling, water leaking from the indoor unit, and hissing sounds indicating a refrigerant leak.
How much does an evaporator coil replacement cost?
The coil itself plus labor usually runs $1,200 to $2,800 depending on tonnage and access. On an older R-22 system, a full replacement is often the better investment.
HVAC247PRO is a licensed Texas HVAC contractor (TACLB00105442E and TACLA95904E) serving the Houston metro 24/7. Call (346) 451-1559 or book an inspection online and a technician will be at your door the same day.