Huh, I hadn’t thought about turning the light on for short periods. And if ozone is mostly generated with moving air, then turning the light on with the furnace off seems to be safest. Thanks for the suggestion.

Thanks for pointing that out; I was unaware of that. After educating myself a little, it looks like UV light below about 200nm wavelength generate ozone, but 254nm is the sweet spot for killing microbes. The light I got works at the 254nm wavelength.

The US EPA recommends a concentration of less than 70ppb, Canada 40ppb, and the WHO 30ppb. This model has been tested by the California Air Resources Board at 13ppb.

That’s reassuring, but I’m still looking more into this. Do you have any recommended resources for gaining more insight on ozone generation?

https://www.environics.com/2025/02/17/regulations-ambient-ozone-concentration/

https://www.environics.com/2025/02/17/regulations-ambient-ozone-concentration/

https://bioshielduv.com/products/bioshield-magnetic

Thank you, that makes sense. I did not realize the air all gets forced through like that.

What do you mean by “ before it splits?” I’m still learning a lot, but the general consensus of where to place the UV light was on the bottom side of the A-frame, because that’s where the moisture will accumulate and allow for bacteria and fungus growth.

I ended up drilling a hole and mounting the light right into that end plate, and then drilling another hole in my new access panel for the cord, and putting duct putty around the hole.

My friend finally got back to me and said the same thing. I guess I learned something about furnace coils. I ended up making a compromise and just mounting the light into that end plate.

Rex Krueger, Paul Sellers, and Wood by Wright are all great free options online. My favorite people to follow and I wish I had learned about them sooner are Joshua and Mike with Mortise and Tenon Magazine.

The M&T guys approach woodworking from a more traditional angle, as opposed to starting modern and working backwards. I really enjoy their mix of philosophy references and practicing traditions for crafting by learning from the past.

They have some free YouTube videos that are pretty great; Maybe you could watch those and get a feel for what their style is. If their approach is something that resonates with you, the books Worked and Joined are essentially beginners manuals for traditional hand tool woodworking, in the photos are very helpful. They also have other books and magazine authors that specialize in things such as wood carving, green wood, working, and furniture making. They discussed even Native American woodworking with very basic tools, as well as the French group Carpenters Without Borders that only use axes.

Please let me know if I can help direct you in any other way. I absolutely love that I found hand to woodworking as a craft. It is a lifelong endeavor and so rewarding. The struggles are challenging, but make everything very worthwhile. I honestly feel more grounded and more human, making things with hand tools.