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A few years ago I bought a Westinghouse 1701 air purifier that advertised medical-grade air purification and particulate eradication. It worked for about a year. Then one day it powered on but the fan/blower wouldn’t work. I stashed it in the closet to figure out at a later time.

Many online comments said that it was somewhat common for this model to suddenly stop working. Also, users remarked that the company had quietly discontinued this model and were not servicing the broken ones. Hmmm.

I recently had a free afternoon to pull this apart and see if I could solve it. This unit used two filters, one of them a “reactor core” (I had bought two spares of this when I purchased this, they come sealed).

The first thing I noticed was two visible rusty screws behind the filters. That seemed unusual for something that’s been living in my bedroom and closet in a pretty dry climate location. Another online commenter had also noted rust on his fan. It seemed this was a common issue.

The unit nests together in many pieces, and as I continued to take it apart, I indeed found more rusty screws. Still, my hunch was that I could probably find a bad capacitor and swap it out to bring this thing back to life

The power supply looked fine, which makes sense because it was powering on, just not blowing air.

The fan was a typical hamster wheel style blower and although I noticed surface rust inside of it, the motor spun smoothly and freely. This was not a case of a seized motor.

At this point I was still disassembling the unit to try to find the control board, hoping for that easy capacitor fix. This thing was built many layers deep. Finally, I pulled off an internal plastic shroud and found the control board. The problem was immediately clear and it was not a capacitor.

One of the transistors, probably a MOSFET, looked like it had been dissolved in acid. This wasn’t going to be an easy capacitor-replacement repair after all.

At this point, I decided to cut my losses, and started trying to figure out what I could strip out and salvage for my parts bin. The power adapter and brushless motor both seemed worthwhile to keep around. But there was one component I did not recognize.

I looked it up online. The information was pretty alarming. Its label, 臭氧发生器, translates to "ozone generator." So this unit was generating ozone as part of its air “purification,” which is actually controversial and considered harmful by the EPA at the levels some of these devices produce.

Ozone (O₃) is a highly reactive molecule that oxidizes and breaks down organic compounds like mold, bacteria, odors, VOCs. The idea is that it chemically destroys pollutants rather than just trapping them in a filter. Apparently manufacturers market it as a “deep clean” for the air.

O₃ attacks pollutants, and also your lung tissue. The EPA is direct about this. Ozone is a known respiratory irritant at even relatively low concentrations. Symptoms include coughing, chest tightness, throat irritation, and aggravated asthma. Long exposure is linked to reduced lung function.

EPA info: www.epa.gov/ground-level...