Can I use Lysol on the indoor coils of an A/C?

Factual Questions
1

At the end of the summer, we had some flooding problems in our basement due to abnormally higher than average rainfall. So, in order to make repairs, our outdoor compressors had to be disconnected and moved away from the house in order for the foundation guys to dig a trench.

When they were reconnected (about a week later), the first time the A/C came on, we noticed a sour/mildewy smell- like when laundry sours. I suspect it’s from moisture that accumulated on the inside air handler during the foundation repairs.

Can I use something like Lysol on the coils to kill the mildew/mold and make the odor go away?

(This is a heat pump system.)

2

I woudl think that or if you could spray some shower mildew killer into there it would do the trick pretty good, then run the heater until all the moisture in there is evaporated.

3

The “proper” product for this purpose is called Frigi-Fresh. You can probably find it at a well-stocked auto parts place that caters to pros and it costs about 12-15 bucks a can.

I’ve seen concerns with Lysol being corrosive to some air conditioner evaporators - specifically the aluminum parts.

Fridgi-Fresh is primarily an automotive product (due to the system design, and how people use them, car air conditioners are far more likely to get funky than home systems) but there’s no reason it can’t be used on a home system.

Can you easily get at the evaporator coil? Usually on home systems, you need to remove a panel to find it.

Another thing to try is simply crank up the heat and bake the nasties out.

4

As the air inside the vents cools, would condensation cause the same problem all over again? How long would the heat have to run (and how hot)?

5

Lysol is fairly basic stuff: (Potassium hydroxide, 3-4%, pH around 9)
The aluminum cooling fins on an AC are not going to like that too well, so if you use it, rinse with water afterwards.

6

Two questions:

  1. Is this something I can do myself or should I suck it up and just call the A/C repair guys?

  2. After any sort of “treatment,” how likely is it that the problem will occur again?

After reading various web sources, I get the impression that the only real way to get rid of the smell is to get a new coil. My system is not even 2 years old, so I’m not ready for that step.