Everyone With an Air Conditioner
Let's start there. Every evaporator coil operates in a wet environment. Every one has condensate acting as an electrolyte. Every one with copper-to-aluminum contact has an active galvanic cell. Every one is corroding, slowly, from the day it's installed.
The coastal home might fail in 5 years. The inland home might last 15. But the mechanism is the same. The destination is the same. The only question is when.
Especially: Challenging Environments
Coastal Properties (Within 15 Miles of Salt Water)
Salt air doesn't stop at the beach. Elevated chloride levels exist miles inland. Warranty exclusions specifically target these installations. Equipment life is dramatically shortened.
Mitsubishi Electric warranty states:
"THIS LIMITED WARRANTY DOES NOT COVER: operating the System in a corrosive or wet environment... including sea- or salt-water"
Trane/American Standard requires:
"Indoor and outdoor coils will only be covered if a Sea Coast Kit is installed"
If you live within a few miles of the ocean and didn't pay extra for special coastal protection at time of purchase, your coil failure may not be covered at all.
Pool and Spa Facilities
Chlorine is explicitly excluded in nearly every warranty. Indoor pool buildings are HVAC graveyards—the combination of humidity, heat, and chlorine vapor is extraordinarily aggressive.
Lennox explicitly excludes:
"Installation or operation in a corrosive atmosphere, or otherwise in contact with corrosive materials (e.g., chlorine, fluorine...)"
Fujitsu excludes:
"Chlorinated water or vapor (such as in an enclosed pool area)"
Agricultural Operations
Livestock facilities generate ammonia. Fertilizer storage releases corrosive vapors. These environments are explicitly excluded from warranty coverage, and equipment failure is expected rather than surprising.
Lennox excludes:
"...recycled waste water, urine, fertilizers, or other damaging substances or chemicals"
Humid Climates
Houston, Miami, New Orleans, Atlanta, Tampa—anywhere with high humidity means more condensation, more electrolyte, more corrosion current. Systems run more hours, produce more condensate, and corrode faster.
New Construction & Spray Foam Houses ⚠️ HIGHEST RISK
New homes are full of volatile organic compounds off-gassing from paint, adhesives, carpets, plywood, and insulation. These compounds include formic acid and acetic acid—drivers of "formicary corrosion" that creates microscopic tunnels through copper tubing. You can't see it until the coil fails.
But spray foam insulation creates an even more dangerous environment:
- Spray foam traps VOCs inside the building envelope, creating concentrated acidic vapors
- Airtight seal prevents escape of corrosive compounds, forcing them to circulate through your HVAC system
- Accelerated corrosion - spray foam homes experience coil failures 2-3x faster than traditional construction
- No warranty protection - manufacturers exclude "environmental factors" that include VOC exposure
If you have a new home with spray foam insulation, CoilShield protection is not optional—it's essential. The combination of trapped VOCs and continuous HVAC operation creates the perfect storm for formicary corrosion.
Industrial/Chemical Environments
Carrier/Bryant excludes:
"Failure or damage due to... corrosive environments"
Any commercial or industrial setting with chemical exposure—manufacturing facilities, water treatment plants, laboratories—falls outside warranty protection.
Especially: Anyone Who Values Their Time and Comfort
- The family that can't afford two weeks without AC in August
- The remote worker whose productivity depends on a comfortable home office
- The household with elderly members or infants
- The business that can't close for a week waiting for HVAC repairs
- Anyone who's ever experienced AC failure and swore "never again"
The Bottom Line
For normal residential installations, warranty will likely cover the part—but you still face $850-$2,400 in labor and refrigerant costs, plus 1-3 weeks without AC.
For challenging environments (coastal, pools, agricultural, industrial), many manufacturers exclude coverage—check your warranty.
But for everyone—you still face the labor costs, the refrigerant costs, the downtime, and the misery when a coil fails. CoilShield helps prevent that failure in the first place.
We don't replace or extend manufacturer warranty. We focus on prevention: proven cathodic protection so you can avoid the cost and disruption of premature coil replacement.
Find out which CoilShield system is right for your environment today.
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