Most HVAC contractors and homeowners seeing an increase in leaking coils in recent years, and many are wondering what is causing this issue. The major manufacturers state the failure rate caused by manufacture defects are only in the 2%-3% range, but HVAC contractors and homeowners seem to be feeling the impact of coil failure rates much higher than that….so what is going on, and are coil leaks preventable?

A major cause of evaporator coil leaks, is formic acid. which causes corrosion and weakens the metal tubes the coils are made of…..and has your A/C or Heat Pump system operates at high pressures small leaks will develop in the coil. With the newer efficency standards required by regulators, today’s systems operate at pressures between 2-3 times that of pressure levels in units made just 10 years ago, and the coil tubes do seem to be thinner now than what we saw years ago. Formic acid is produce when volatile organic compounds (VOC) react with the copper/aluminium metal that the coil is made off. VOCs are introduced into homes from from the vapor released from cleaning agents , aerosol cans, air fresheners, carpets, new construction material (carpets, foam cushions in furniture) and just about any material that is manufactured via a chemical process.

So what can be done to reduce the likelyhood your evaporator coil will fail before it’s time? Here are some ideas:

Reduce the use of VOC’s.
If possible, bring in fresh air into the HVAC system to help dissipate the VOCs. This is espeically important on homes that are of new construction, or even older homes that have had their crawlspaces sealed, windows replaced, and more insulation installed (such as foam spray insulation). These home don’t have enough fresh air entering the home and VOC levels become highly concentrated in the duct system as your HVAC system operates.
Use a whole house air purifier that is design to neutralize VOC through the use of ultraviolet light. The sun produces ultraviolet light naturally and it neutralizes VOC’s naturally….inside your duct system an ultraviolet light can greatly reduce VOC levels, as well has provide other benefits. The problem is sunlight does get inside inside your duct system and near your evaporator coil, but an air purifier/UV light can replicate the benefits of sunlight.
Install a UV coil lamp in sight of the coil to keep growth and bacteria from covering the coil. This will provide cleaner air for you and your family to breath, as well as provide coil protection by reducing bacteria growth which clogs air flow between cleanings. A UV Coil lights keep a coil that is maintained clean, but will will not effectively clean a dirty coil that is already covered with dust and surface corrosion.
Regularly cleaning and servicing the coil will slow acid build up. A regularly serviced and cleaned HVAC system will result improved efficiency, longer coil life, provide cleaner air inside your home, and the system runs at less refrigerant pressures vs, a system that has dirty in door and outdoor coils. Lower pressure means there will be less of a chance that a weak place in the coil will result in a major leak.
New Construction HVAC systems do not seem to last as long as new systems put into existing homes……so putting in a UV light in new construction is highly recommended.

Call us today for more info and details on a coil inspection, and or starting an annual maintenance plan to ensure your HVAC system coils remain clean!


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