Your Coil Is Under Constant Attack
To understand why CoilShield matters, you need to understand what's happening inside your air handler every time your system runs.
Your evaporator coil faces multiple corrosion threats simultaneously. Most failures result from a combination of these factors:
The Chemistry of Cooling
Your evaporator coil works by being cold—cold enough that water vapor in your home's air condenses onto its surface, just like water beading on a cold glass of iced tea. This is how your AC dehumidifies: it literally wrings moisture out of the air.
That condensate water then drains away through the condensate line.
Simple, right?
Here's the problem: that condensate isn't pure distilled water. It contains:
- Dissolved carbon dioxide from the air (making it slightly acidic)
- Dissolved oxygen (enabling oxidation reactions)
- Dust, pollen, and particulates from the air
- Volatile organic compounds from household products
- In some cases, acidic compounds that cause "formicary corrosion"
This condensate coats your coil surfaces constantly during operation. And it doesn't just sit there—it creates an active electrochemical environment.
The Galvanic Corrosion Problem
Modern evaporator coils are engineering marvels of efficiency. They're also electrochemical time bombs. Here's why:
To maximize heat transfer while minimizing cost, manufacturers build coils from:
- Aluminum tubes (excellent heat transfer, lightweight, inexpensive)
- Aluminum fins (maximize surface area)
- Copper connections (required for refrigerant line brazing)
The problem? When copper and aluminum are in contact in the presence of an electrolyte (like condensate water), they form a galvanic cell—essentially, a battery.
From the Carrier/Bryant CAAMP Installation Manual:
"CAUTION: Take precautions to ensure Aluminum tubes do not come in direct contact or allow for condensate run off with a dissimilar metal. Dissimilar metals can cause galvanic corrosion and possible premature failure."
Current flows. Electrons move. And the aluminum—being more "active" electrochemically—corrodes preferentially to protect the more "noble" copper.
Your coil is literally eating itself at every copper-to-aluminum joint, every hour it operates.
How Thin Is the Line Between Working and Leaking?
The Carrier 37MHRAQ mini-split specification sheet lists the evaporator tube wall thickness: 0.24mm
That's 0.00945 inches. Less than 1/100th of an inch.
That's all that separates your refrigerant from your living room. That's all that stands between "comfortable" and "catastrophic." And galvanic corrosion is working on that barrier every day, every condensation cycle, every summer.
Formicary Corrosion: The Invisible Threat
The most insidious type—microscopic tunnels that branch through the metal like ant colonies. Organic acids from VOCs (formic acid, acetic acid) create branching tunnels inside copper tubes. You can't see it until the coil fails.
New homes are full of VOCs off-gassing from paint, adhesives, carpets, and insulation. These compounds include formic acid and acetic acid—drivers of "formicary corrosion" that creates microscopic tunnels through copper tubing.
The Aluminum Vulnerability
Modern all-aluminum coils (like Lennox's Quantum™ line) eliminate some galvanic couples but introduce new vulnerabilities:
From the Daikin/Goodman/Amana Installation Manual:
"Even a one-time application of these corrosive chemicals can cause premature aluminum evaporator coil failure. Any cleaners that contain corrosive chemicals including, but not limited to, chlorine and hydroxides, should not be used."
From the Lennox Installation Manual:
"When cleaning coil, keep pH of cleaning solution between 5 and 9... Corrosive buildup (such as salt) should be cleaned as required but no less than several times per year in coastal environments."
One wrong cleaning product. One time. And your coil's lifespan is compromised.
Aluminum is an "amphoteric" metal—it's attacked by both acids AND bases. The safe pH window is narrow, and household cleaners routinely fall outside it.
Environmental Stress
Humidity, temperature cycles, and intermittent wet/dry conditions accelerate all these processes. 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.
The Solution: Cathodic Protection
CoilShield uses cathodic protection—technology proven in marine and pipeline applications for 200 years—to prevent all forms of coil corrosion.
By making your coil the cathode in an electrochemical cell, corrosion becomes thermodynamically impossible. The reaction simply cannot proceed.
Whether it's galvanic corrosion, formicary corrosion, acidic attack, or environmental stress, CoilShield provides continuous protection against all corrosion types.
Don't wait for your coil to fail. Protect it now with CoilShield.
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