Professional Evaporator Coil Services in Friendswood, TX

A frozen evaporator coil is a problem anywhere, but in a humid climate like Galveston's, it's significantly more damaging. When that ice melts — and it will, rapidly — the volume of water released overwhelms drain pans and condensate lines. In dry climates, a frozen coil thaws and you get a small puddle. On the Gulf Coast, you get a flood that soaks ceiling drywall, saturates insulation, and creates the exact moisture conditions that breed mold growth in hours. It's one of the most common causes of interior water damage in Galveston homes, and it's almost always preventable.

Why Evaporator Coils Freeze on the Coast

The evaporator coil sits inside your air handler, absorbing heat from the air that blows across it. When something disrupts this process, the coil temperature drops below freezing and moisture from the air ices over on the coil surface. In Galveston, where the air passing across that coil carries far more moisture than in drier climates, ice builds up fast. A coil that might frost lightly in Phoenix becomes a solid block of ice in Galveston within 30-60 minutes.

The three main causes:

Low refrigerant. This is the most common cause in coastal systems. Salt corrosion on copper refrigerant lines creates pinhole leaks that slowly drain your system's refrigerant charge. As the refrigerant level drops, the remaining refrigerant expands too much in the evaporator coil, dropping its temperature below freezing. The coil ices over, airflow drops further, and the ice builds on itself. By the time you notice warm air from the vents, the coil may be completely encased.

Restricted airflow. A clogged air filter is the obvious culprit, but in Gulf Coast homes we also see collapsed duct sections (the flexible ductwork in attics sags and crimps over time), closed or blocked supply registers, and failing blower motors that aren't pushing enough air across the coil. Without sufficient airflow, the coil can't absorb enough heat to stay above freezing.

Dirty coil surface. Even in a system with proper refrigerant and airflow, a coil coated in dust, mold, and debris acts as an insulator. The dirt layer prevents the coil from efficiently absorbing heat from the passing air. The coil runs colder than designed, and in our humidity, frost forms quickly on the contaminated surface.

The Coastal Corrosion Factor

Salt-contaminated air doesn't just attack your outdoor condenser — it gets pulled through your indoor system too. Over time, salt particles deposit on the evaporator coil surface, accelerating corrosion of the copper tubing and aluminum fins. A corroded evaporator coil develops micro-leaks that allow refrigerant to escape, creating the low-charge condition that causes freezing. It also provides a rough, pitted surface that traps more dust and mold, compounding the problem.

In systems where the indoor air handler pulls air from a space connected to the outside — like a garage, utility room, or an unconditioned closet — salt infiltration on the evaporator coil is significantly worse. We see coils in these installations that need replacement 3-5 years sooner than coils in properly sealed air handler closets.

Evaporator Coil Cleaning

Professional coil cleaning should be part of every coastal AC tune-up. Our $129 tune-up (regularly $225) includes evaporator coil inspection and cleaning because skipping this step in Galveston's climate leads directly to the problems described above. We use a no-rinse evaporator coil cleaner that dissolves salt deposits, mold, and organic buildup without flooding the drain pan. For heavily contaminated coils, we use a pressurized cleaning process that removes stubborn deposits.

The difference in performance after a proper coil cleaning is measurable. We routinely see a 10-15 degree improvement in temperature split (the difference between return air and supply air temperature) after cleaning a neglected coastal evaporator coil. That translates directly to better cooling, lower humidity, and reduced CenterPoint Energy bills.

Evaporator Coil Replacement

When corrosion has compromised the coil beyond what cleaning can fix — visible green patina on copper, pinhole leaks, or fins that disintegrate when touched — replacement is the only real solution. An evaporator coil replacement typically runs $800-$2,500 depending on the coil size, refrigerant type, and accessibility.

For coastal replacements, we recommend coils with factory-applied corrosion coatings when available. Not all manufacturers offer coated evaporator coils (it's more common on condenser coils), but for systems in high-exposure locations, the added protection is worth seeking out. We also verify that the air handler cabinet is properly sealed after coil installation to minimize salt air infiltration from unconditioned spaces.

What to Do If Your Coil Is Frozen Right Now

Turn your thermostat to "fan only" — not "off." Running the fan circulates room-temperature air across the frozen coil, thawing it gradually. Place towels around the air handler base and check the drain pan. Do not chip ice off the coil — you'll damage the delicate fins and potentially puncture the copper tubing. Let it thaw completely (1-3 hours depending on the ice thickness), then call for service before turning the cooling back on. Running the system with whatever caused the freeze will just freeze it again.

We service evaporator coils across Galveston, Texas City, League City, Dickinson, La Marque, and Santa Fe. If your coil has frozen, is leaking refrigerant, or hasn't been professionally cleaned in over a year, the salt and humidity on the coast are working against you every day you wait.