The Hidden Threat in New Homes
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.
What Is Formicary Corrosion?
Formicary corrosion is the most insidious type of corrosion—microscopic tunnels that branch through the metal like ant colonies. Organic acids from VOCs (formic acid, acetic acid) create branching tunnels inside copper tubes.
Unlike galvanic corrosion, which attacks from the outside, formicary corrosion attacks from within. The tunnels start at the inner surface of the copper tube and branch outward, creating a network of microscopic passages that eventually lead to leaks.
Why New Construction Is Vulnerable
New homes are particularly vulnerable because:
- Fresh paint releases formic acid and acetic acid as it cures
- Adhesives and sealants contain VOCs that off-gas for months or years
- Carpets and padding release VOCs, especially when new
- Plywood and particleboard contain formaldehyde and other VOCs
- Insulation materials can release VOCs
These compounds circulate through your home's air, condense on your evaporator coil, and create the acidic environment that drives formicary corrosion.
Spray Foam Insulation: The Hidden Corrosion Accelerator
Spray foam insulation creates an especially aggressive environment for formicary corrosion. Unlike traditional insulation, closed-cell spray foam creates an airtight seal that traps VOCs inside your home's building envelope.
Why Spray Foam Is Particularly Dangerous
- Trapped VOCs: The airtight seal prevents VOCs from escaping, creating concentrated acidic vapors
- Continuous Exposure: VOCs circulate through your HVAC system for months or years after installation
- Accelerated Corrosion: Higher VOC concentrations mean faster formicary corrosion development
- No Escape Route: Unlike homes with traditional insulation where VOCs can dissipate, spray foam homes trap these corrosive compounds
The Result: Homes with spray foam insulation experience coil failures 2-3x faster than traditional construction due to the concentrated VOC environment.
CoilShield Protection: Installing CoilShield from day one in spray foam homes is critical—the protection prevents formicary corrosion during the highest-risk period when VOC off-gassing is at its peak.
The Invisible Threat
Formicary corrosion is particularly dangerous because:
- It's invisible—you can't see the tunnels forming inside the copper
- It's progressive—once it starts, it continues until the coil fails
- It's unpredictable—failure can occur anywhere from months to years after installation
- It's not covered by warranty if attributed to "environmental factors"
The CoilShield Solution
CoilShield's cathodic protection prevents formicary corrosion by making the copper tube the cathode in an electrochemical cell. When the tube is cathodically protected, it cannot corrode—whether from galvanic corrosion, acidic attack, or formicary corrosion.
By installing CoilShield in new construction, you protect your HVAC system from the moment it's installed, preventing VOCs from causing formicary corrosion in the first place.
Prevention Beats Replacement
Don't wait for formicary corrosion to destroy your new home's HVAC coil. Protect it from day one with CoilShield's proven cathodic protection technology.
Learn more about CoilShield protection for new construction today.
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