Evaporator coils are a very common place to have refrigerant leaks but why?
(Last video cut off this one is corrected)

Several Causes we discuss in this video.

Evacuation and dehydration. When we don't pull a proper vacuum, moisture is left inside the lines. that moisture turns to acid especially with POE oil. the acid eats away from the inside out and even causes copper plating on the compressor and compressor failure.

Efficiency, as the government mandates higher efficacy manufactures come up with new ways to transfer heat.
One of those is riffling or internal grooving. this allows better heat transfer properties from the refrigerant to the copper. it allows the refrigerant to tabulate or spin increasing contact time but the grooves also allow a place for acids to eat away easier.
Second way is smaller tubbing and thinner copper. Thinner material means faster heat transfer and also savings for the manufacture but this has a higher likelihood of refrigerant leaks.

Electrolysis or more specific galvanic action where the very presence of dissimilar metals sets up a potential (or voltage) between two metals through an electrolyte (usually water). Copper, aluminum, galvanized metal, condensation and air movement all contribute to this on the evaporator coils.

Household chemicals. We have more chemicals in our homes than ever before. these chemicals react to the copper and start causing leaks form the outside in. There are two main forms of pitting corrosion found in indoor coils: (1) general pitting; and (2) formicary corrosion, sometimes called “ant’s nest” corrosion.
Common household substances that may contain chlorides include:
Air Fresheners, Aerosol sprays Carpeting, Paint removers Degreasing and detergent cleaners, Tub and tile cleaners Dishwasher detergents, Vinyl fabrics Laundry bleach, Vinyl flooring Fabric softeners, Wallpaper Pool/Spa Chemicals, Common household sources that may contain formic acid, formaldehyde, of formate include:
Building materials, Adhesives, Cabinets, Carpets
Countertops, Foam insulation, Laminates, Paints (latex and oil based), Paneling, Plywood, Particle boards, Cosmetics, Disinfectants and deodorizers, Tobacco and wood smoke
Typical household sources of acetic acid or acetate include:
Building materials, Adhesives, Cabinets, Carpets, Countertops, Foam insulation, Laminates, Paints (oil based), Paneling, Particle boards, Plywood, Silicone caulking, Wallboard, Wallpaper, Cleaning solvents, Vinegar

Improper maintenance
DO NOT PUT BLEACH IN THE AC DRAIN!!!! Copper is very corrosive and should not be used. They make products such as viper drain cleaner that uses enzymes and are not corrosive.

Improper Coil Cleaning procedures and chemicals. The cleaning adjent used is very hard on the evaporator coils and can cause leaks. the proper chemical must be used and that chemical MUST be completely rinsed off. It may take multiple tries and effort to rinse off al the chimerical.

Damage form screws, mishandling, shipping or even vibration.


Linkes and sourced of information and pictures used

Viper drain cleaner (NOT SPONCERED, NO AFFILIATION)
https://www.refrigtech.com/viper-pan-...

york talk leaks article
https://yorkcentraltechtalk.wordpress...

leak pictures and causes
http://www.centralairsys.com/coilCorr...

Air fresheners chemicals
https://ehs.umass.edu/air-fresheners-....

https://www.sciencedirect.com/science...

https://www.madesafe.org/toxic-chemic...

https://www.poison.org/articles/air-f...
coil cleaning products cause corrosion https://permatron.com/prevent-install...

https://www.cdc.gov/nceh/publications....

Kristi Ohr air freshners
https://ehs.umass.edu/air-fresheners-....

Copper corrosion
https://www.goodway.com/hvac-blog/201...
Copper tubing size
https://www.racplus.com/features/redu...

copper groves
https://www.copper.org/applications/p...


https://hvac-talk.com/vbb/threads/275...

class action lawsuits
https://www.classaction.org/air-condi...

https://classactionsreporter.com/good...

https://www.clg.org/Class-Action/List...

https://www.evaporatorcoillawsuit.com...

https://www.classlawgroup.com/hvac/