Thread: Acid sprayed inside new AC condenser

I was performing a warranty inspection yesterday on a 11 month old house. Right before the owners moved in, the builder had the brick cleaned with a cleaning agent (likely muratic acid) and a power washer. The inside of the AC condensers were etched from contact with the cleaning agent (likely muratic acid). The aluminum coils, copper lines, and fans all had etching and discoloration. The aluminum coils had actually deteriorated somewhat from acid contact. The outside painted cover of the condensers looked fine so it would be easy to walk right past this and not notice what the acid had done, unless one stopped and looked down into the condenser. The photos were taken nearly at dark so it is hard to see.
IMG_8500.jpgIMG_8502.jpgIMG_8498.jpg

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Its hard to tell from the photos how bad this is. If the aluminum was partially deteriorated I would call for replacement. You could email the manufacturer and ask them whether this is cause for concern or would affect warranty coverage. If they say yes it gives you more ammo. I find that builders often think everything is fine, so more ammo may help.

Muratic acid attacks and consumes aluminum and there is no telling how long the acid was on the unit. I called for replacement. Thanks

Good catch, the kind of unexpected thing we need to watch for.

The builder doesn't want to replace it of course. The metal coils and lines have been compromised and I have to think it that it may affects the long term performance, meaning an eventual leak.

Originally Posted by Gene South

The builder doesn't want to replace it of course. The metal coils and lines have been compromised and I have to think it that it may affects the long term performance, meaning an eventual leak.

While I rarely get involved in dealing directly with builders, I would likely tell my client to check with the a/c manufacturer for their ruling (in writing) about what this does to their warranty.

I have to think they would void the warranty for problems caused by external corrosion issues. (seems I have seen verbiage to this effect in the standard warranty document)

Then ask the builder to step up to the plate with a warranty (parts and labor) against corrosion damage and leaking (in writing) for the expected life of the unit or replace it now. This is likely a $3,000 issue for the builder now, but a $5,000 to $6,000 to the customer later. Something they should fight for unless that is chump change to them.

Good catch Gene.

Looks like the brick guy will be buying them a new unit and learn an important lesson about being careful with acid wash.

Thanks for the input Jim.

Gene.

How do you know it's muratic? Several years ago, I found an A/C condenser that was heavily corroded. However, I assumed dog urine.

Originally Posted by Gunnar Alquist

How do you know it's muratic? Several years ago, I found an A/C condenser that was heavily corroded. However, I assumed dog urine.

Because of the spray pattern on the equipment and the builder is using muratic acid. No dogs on this property. I wasn't there when it happened but all signs point to what I reported. I have seen plenty of dog urine corrosion. I know what that looks like. This wasn't like that.

Originally Posted by Gunnar Alquist

How do you know it's muratic? Several years ago, I found an A/C condenser that was heavily corroded. However, I assumed dog urine.

Judging by the height of the damage and the placement, I would not want to have to deal with that dog!

New construction and muriatic acid for brick cleaning is standard operating procedure around here.

It's best to describe conditions such as the one described in this instance by using the phrase "consistent with” rather than making a definitive statement regarding the cause of the corrosion, e.g., " Corrosion is present on metal components located the inside of the air conditioning system compressor/condenser unit. This is consistent with overspray from acidic materials used to clean the exterior masonry veneer at the time of original construction."

Bleach will do that.

Originally Posted by Gene South

I was performing a warranty inspection yesterday on a 11 month old house. Right before the owners moved in, the builder had the brick cleaned with a cleaning agent (likely muratic acid) and a power washer. The inside of the AC condensers were etched from contact with the cleaning agent (likely muratic acid). The aluminum coils, copper lines, and fans all had etching and discoloration. The aluminum coils had actually deteriorated somewhat from acid contact. The outside painted cover of the condensers looked fine so it would be easy to walk right past this and not notice what the acid had done, unless one stopped and looked down into the condenser. The photos were taken nearly at dark so it is hard to see.
IMG_8500.jpgIMG_8502.jpgIMG_8498.jpg

I didn't have to guess what happened to the one I did on Tuesday......

myth busted...probably

before this starts a non-issue copper patina reporting trend
i had to test
i sprayed copper pipe with HCL/muriatic acid
allowed to dry
CLR on q-tip used to clean instead of baking soda & water...the Bride says her cooking supplies are above my pay grade

unless the piping is pitted/physically damaged have builder apply an approved neutralizer and rinse off patina if any is left behind
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